OA11343A - Apparatus and method for transferring entropy withthe aid of a thermodynamic cycle. - Google Patents

Abstract

The invention relates to a method and device for entropy transfer, whereby a periodic cyclic process is created inside a pressurized container by periodically exchanging working substance(s) using valves at different pressures and by periodically modifying partial volumes defined by regenerators with or without the use of a compression device. The transformation of mechanical energy by exchanging a working substance at different pressures makes it easier to integrate other partial systems and to substantially modify the temperature of at least one working substance flow by coupling a thermodynamic cyclic process to heat energy transport, heat energy storage or the construction of a simple effective solar collector system wherein optical concentration, translucent insulation and translucent insulation cross-flow are combined in an effective manner. The invention can be used for solar energy or heat sources or to supply local pumping capacity requirements and provide mechanical actuation, electrical energy, heat, cold, cleaning or separation and chemical or physical modification of at least one substance.

Description

011343

Apparatus and method for transferring entropy with theaid of a thermodynamic cycle

Description 5

Problem:

In the case of the transfer of entropy as, forexample, in the use of solar energy or heat sources,such as the combustion of biomass, waste heat or10 geothermal heat, for example, for a required localsupply for pumping power, mechanical drive, electricalenergy, for provision of heat, the production of cold,cleaning or separating or the Chemical or physicalalteration of at least one substance by coupling to a15 periodically proceeding thermodynamic cycle, the aim isto render as low as possible the necessary outlay onenergy carriers or mechanical energy, as well as thedesign, technological, · financial or ecological outlayfor 20 · the construction of the entire apparatus, or the operating sequence of the entire method, • the thermal or mechanical energy transport(s)required in this case, • the methods or apparatuses which can be used in this25 case for the mechanical energy conversion, or • an integrated- energy storage mechanism.

The thermodynamic cycles used so far· (Stirlingengine, steam turbine) are coupled in each case to twoheatbaths at a constant température. 30 As a resuit, energy transport can be performed onlyoptically (in conjunction with parabolie mirrors oroptical conductors) are via a material flow with aphase transition (heatpipe).

Because the aim is an isothermal èxchange of heat 35 energy, the thermal energy can be stored only in

Chemical stores or in PCM devices.

As a resuit, the outlay on concentrating the energy by the collector, on the transport and on a storage which

9 Μ 011343 - 2 - is désirable for many applications becomes ail toooften excessive. -

If the aim is direct supply with cold or compressedair, for example, with as little an outlay as possible 5 on apparatus, it is necessary in the case of many knownSystems to select the path passing via the interface ofelectrical power.

Object 10 In the case of a method and/or an apparatus for transferring entropy as in the use of solar energy orheat sources, such as the combustion of biomass, wasteheat or geothermal heat, for example, for a requiredlocal supply for pumping power, mechanical drive, 15 electrical energy, for provision of heat, theproduction of cold, cleaning or separating or theChemical or physical alteration of at least onesubstance by coupling to a periodically proceedingthermodynamic cycle, whose efficiency is as high as 20 possible, the central object of the invention is toz render as low as possible the necessary outlay on energy carriers or mechanical energy, as well as thedesign, technological, financial or ecological outlay for 25 · the construction of the entire apparatus, or the operating sequence of the entire method, • the thermal or mechanical energy transport(s)required in this case, • the methods or apparatuses which can be used in this 30 case for the mechanical energy conversion, or • an integrated energy storage mechanism.

Essence of the invention

According to the invention, this object is 35 achieved by means of an apparatus and a method fortransferring entropy, in which at least one workingvolume filled with a working fluid is largely delimited from other spaces or the surroundings, by at least one 011343 - 3 · valve and at least one pressure housing, optionallywithout or with a mechanical compression device suchas, for example, one or more pistons, liquid pistons ordiaphragms, and optionally at least one liquid boundary5 surface or none, in which • in each case at least two mutually delimitablestructures or structural éléments through whichworking fluid is to flow in a period with a maximumquantity and which hâve heat transfer surfaces 10 necessarily active for the thermodynamic process, inwhich in the operating State in each case isothermalsurfaces of different température which are to beflowed through by the working fluid are formed, • optionally at least one or no element or structural 15 element such as for example, a (foldable) diaphragm, folded, telescopic or résilient sheets, a regeneratorstructure of changeable shape or. a liquid boundarysurface, which is arranged between said structures orstructural .éléments in a connecting and largely20 sealing fashion or is equipped with the action of aregenerator, • or at least one or no displacer piston which can bemoved in this working volume, • and the limitation of the working fluid 25 delimit at least one partial .volume with a minimum sizein . a fashion largely free from overlap with acomparable volume and are partly caused by controlSystem éléments acting thereon by which, predominantlyin those time periods of the periodically proceeding 30 thermodynamic cycle, the ratio of this partial volumeto this working volume is either enlarged or reducedduring which the size of this working volume is changedin size only to a lesser degree and, depending on thepressure of the working fluid in this working volume, 35 in each case at least one spécifie valve whose opening and closing times decisively influence " the thermodynamic cycle, and which valve can delimit this working volume from at least one external space which Ο i1343 is filled up with at least one working means inconjunction with partially differing pressures whichare subjected to fluctuations which are only smallerrelative to the periodic pressure change in this 5 working volume during these time periods, isprédominantly (in the time periods characterized above)held open by the control System or the flow pressureand flowed through, which (valve) is held closed duringother time periods which proceed between these time 10 periods and in which the pressure of the working fluidin this working volume either rises or falls throughthe displacement of the above-named or further components or structural éléments by the control Systemand the variation thereby caused in the mean 15 température of the working fluid in this working volumeand/or by a variation in the size of this workingvolume by the mechanical compression device, and theratio of each partial volume as defined above to thisworking volume is varied only to a decisively lesser 20 extent, wherein during a time interval which is muchlonger relative to the period there is either anabsorption or output of thermal energy at least of onesubstance of a continuous or periodically swelling andsubsiding mass flow in conjunction with a sliding 25 température or with a plurality of température levels,and in this working volume at least one working meansacts at least partially as a working fluid whichtraverses the periodic thermodynamic cycle.

The method according to the invention proceeds 30 in an apparatus, according to the invention, fortransferring entropy, in which at least one working volume filledwith a working fluid is largely delimited from otherspaces or the surroundings, by at least one valve and 35 at least one pressure housing, optionally without or with a mechanical compression device such as, .for example, one or more pistons, liquid pistons or 011343 - 5 - diaphragme, and optionally at least one liquid boundarysurface or none, in which • in each case at least two mutually delimitablestructures or structural éléments through which 5 working fluid is to flow in a period with a maximumquantity and which hâve heat transfer surfacesnecessarily active for the thermodynamic process, inwhich in the operating State in each case isothermalsurfaces ôf different température which are to be10 flowed through by the working fluid are formed, • optionally at least one or no element or structuralelement such as for example, a (foldable) diaphragm,folded, telescopic· ot résilient sheets, a regeneratorstructure of changeable shape or a liquid boundary 15 surface, which is arranged between said structures orstructural éléments in a connecting and largelysealing fashion or is equipped with the action of aregenerator, • or at least one or no displacer piston which can be 20 moved in this working volume, • and the limitation of the working fluid delimit at least one partial volume with a minimum sizein a fashion largely free from overlap with acomparable volume and are partly caused by control25 systém éléments acting thereon by which, predominantlyin those time période of the periodically proceedingthermodynamic cycle, the ratio of this partial volumeto this working volume is either enlarged or reducedduring which the size of this working volume is changed30 in size only to a lesser degree and, depending on thepressure of the working fluid in this working volume,in each case at least one spécifie valve whose openingand closing times decisively influence thethermodynamic cycle, and which valve can delimit this35 working volume from at least one external space whichis filled up with at least one working means inconjunction with partially differing pressures whichare subjected to fluctuations which are only smaller 011343 - 6 - relative to the periodic pressure change in thisworking volume during these time periods, ispredominantly (in the time periods characterized above)held open by the control System or the flow pressure 5 and flowed through, which (valve) is held closed duringother time periods which proceed between these timeperiods and in which the pressure of the working fluidin this working volume either rises or falls throughthe displacement of the above-named or further 10 components or structural éléments by the control Systemand the variation thereby caused in the meantempérature of the working fluid in this working volumeand/or by a variation in the size of this workingvolume by the mechanical compression device, and the 15 ratio of each partial volume as defined above to thisworking volume is varied only to a decisively lesserextent, wherein during a time interval which is muchlonger relative to the period there is either anabsorption or output of thermal energy at least of one 20 substance of a continuous or periodically swelling ands subsiding mass flow in conjunction with a sliding température or with a plurality of température levelszand in this working volume at least one working meansacts at least "partially as a working fluid which 25 traverses the periodic thermodynamic cycle.

The overall cycle in a working volume can be assigned a plurality of cycles, running in parallel,between in each case two heat réservoirs at constanttempératures, when viewed in the light of acceptable 30 idealization. Each heat réservoir of these cycles canbe assigned a partial volume of the working volume,which partial volume is filled with working fluid anddefined as above. At least one substance of acontinuous or periodically swelling and subsiding mass 35 flow is thus heated or cooled either by absorbing or outputting thermal energy in conjunction with ' a température différence which is small relative to the total température change upon contact with the hotter 011343 or colder heat réservoir of these cycles, it beingpossible for the phase or Chemical composition to betransformed.

In order to use the solar energy, at least one5 substance of a continuously or periodically swellingand subsiding mass flow is fed thermal energy inconjunction with a sliding température or a plurality of température levels.

When constructing the integrated collector, the 10 following principles can be very effectively combinedon the basis of the température change over a largetempérature interval: • optical concentration • translucent insulation and 15 · flow through the translucent insulation.

The thermal energy can be exchanged very. efficientlyand cost effectively with the aid of a sensitiveaccumulator which has a large surface, such as a gravelbulk fill, for example, in conjunction with a through 20 flow of working means.

The thermal energy transport can be performed by amovement of a capacitive working means such as air, forexample.

The pressure change of at least one working means also 25 leaves open the possibility of using a highly problem-free infrastructure to transport the mechanical energyor as an interface for simple further transfer ortransformation in order to solve more concrèteproblems. 30 These problems hâve already been taken up in part in Patent DE 3607432 Al. This patent contains areprésentation of the theoretical principles of acycle. Citation: column 3, line 45: "VorliegendeErfindung liefert die Erkenntnisse und praktischen 35 Verfahren, um auch mit einer Wârmezufuhr bei gleitender

Temperatur den Carnot-Wirkungsgrad erreichen zu kûnnen" ("The présent invention provides the knowledge and practical expérience to be able to achieve the Carnot - 8 - 011345 /' efficiency even when feeding heat in conjunction withsliding température."].

The concept for a corresponding heat engine waspresented by the applicant of the cited patent in the 5 conférence volume of the 6th International StirlingEngine Conférence 1993, 26 - 27 - 28 May in Eindhoven(Netherlands).

The cited patent does not set forth a physical(phase) and/or Chemical change by a transformation of 10 thermal energy over a wide température interval,although these problème can be traced back to the samecore problem:

Because of the variable ratio of the partial pressures,liquefying a portion of the gas mixture generally 15 requires extraction of thermal energy over a température interval.

Consequently, when evaporating a gas mixture it isnecessary to feed thermal energy over a températureinterval or in conjunction with a plurality of 20 températures.

Similar statements also hold for a Chemicalprocess in which thermal energy is absorbed or outputin conjunction with a plurality of températures or in a. température interval. 25 The preamble and the main claim of the patent cited in excerpts include a limitation to regenerativedriven machines or heat engines in the case of whichthe working volume available to the working fluid isdivided into only two periodically variable partial 30 volumes by a rigidly connected structure, which is tobe flowed through, of regenerator, cooler and heater asin the known Stirling engines.

Stirling engines with appropriate volumes,température différences and speeds such as the machine 35 described in the cited patent are successively described by an isothermal model.

Cf.: "Studie über den Stand der Stirling-Maschinen

Technik" ["Study on the status of Stirling engine 011343 technology"] ; 1995 in the commission of BMBF; development code: 0326974; page 55 ff, Chapter 3.2 ff.The contact made by the working gas with the cylinderwalls or the heat exchangers adjoining the partial5 volumes exhibits no différence which relates to theapplication of this model.

If this model is applied to the machine described inthe cited patent, it must be established that theworking gas in the heated partial volume of the working10 volume expands predominantly isothermally at thetempérature of Τχ whenever the partial volume cooled atthe température Tk is smaller, and is predominantlyisothermally compressed whenever . the ratio of thepartial volumes is inverse. 15 The working gas in this case traverses a cycle betweentwo heat réservoirs from which or to which thermalenergy is extracted or fed at constant températures ineach case.

Except for the cycle of the working gas, with this 20 machine there is no cycle to which it is possible toassign a relevant area in the temperature-entropy

Z / diagram or in the pressure-volume diâgram. Withoutviolating the second law of thermodynamics, thermalenergy which is fed' to’the" machiné at a température25 below Ti can be transported to the cooler only byirréversible phenomena.

Similarly, thermal energy which is extractèd from themachine above Tk can be transported only beirréversible phenomena and must originate from the30 heater,· since no relevant cycle proceeds in the machinewhich pumps thermal energy from the température levelof the coldest partial volume of the working volumefilled with gas to the higher température level.

It is scarcely to be imagined on the basis of this 35 model that the machine described in the cited patent achieves the object set.

Advantages 011343 -lo-in the case of the apparatuses and/or methods not cited, the mechanical work which is fed (consumed)or output (obtained) during a period of the overallcycle for the purpose of compensating the energy 5 balance is for the most part directly converted duringthe transfer of at least one specified quantity of atleast one flowable substance from one storage spaceinto another storage space at a different pressure.

Other Systems or methods can thereby be integrated 10 simply:

Direct use of the pressure change, for example byreplacing a mechanically driven compressor, ordecoupling the movements in the working volume from thedriving shaft of a turbine or a compressor or the like, 15 which turbine/compressor is driven by the pressuredifférence in the substance flowing (in the closedcircuit), or generates this. It is thereby possible,for example, to drive a generator at the usual angularvelocity, and to achieve a flow rate of the working 20 fluid of the order of magnitude of 1 m/s against theheat transfer surfaces, and a correspondingly lowz température différence in the case of the heattransfer, and this has a positive effect on the ..efficiency and reduces the accélérations, occurring at 25 the control System, and the flow losses.

This permits a design of large volume in which thepressure in the working volume is in the région of theatmospheric pressure and air is used as working fluid,as a resuit of which many problems relating to 30 tightness are defused and interesting applicationsbecome possible (cf. Examples of Application).

Compared with the abstract formulation of theobject as selected above, the cited patent is limitedto cooling or heating a heating or cooling medium by 35 thermal contact with heat exchangers of a regenerative driven machine or heat engine.

This rules out a réduction in the outlay on design or technology for heat exchangers or regenerators, which - 11 - 011343 is achieved according to the invention when heat is fedinto the working volume by virtue of the fact that theheating medium is admitted as a hot gas, for example,into the working volume through valves and output again5 at a lower température through a valve (or valves), asa resuit of which, moreover, the dead volumes of theworking volume can be reduced and, in accordance withexpérience, this is just as favourable for achieving ahigh efficiency as is a functional replacement of the10 relatively small heat transfer surface of the heatexchanger by the very much larger one of theregenerator.

Fresh air can flow at atmospheric pressure into theworking volume through one of the valves, as a resuit15 of which décisive synergy effects can be achieved insome applications.

Thus, for example, hot air can be admitted into aworking volume and be blown out as coder air into aspace at higher pressure, a portion - of the thermal20 energy released during the cooling of the air havingbeen absorbed by the coder. './ Large synergy effects are used in the process when thehot fresh air at atmospheric pressure is heated byexhaust gases of an internai combustion engine, and the25 coder air at higher pressure is used for the purposeof supercharging the internai combustion engine (cf.Examples of Application).

Cost effective parabolicic fluted mirrors can beemployed when solar energy is being used, since the30 working means can heat air with the aid of the solarirradiation, and therefore no environmental anddisposai problems can occur from escaping heating oil,nor is there a need to construct greatly ramifiedabsorber pipeline Systems for generating high pressure35 and steam, and this renders the transport of thermalenergy substantially less problematical.

Moreover, the heating of the working means over a largetempérature interval (for example 200°C to 500eC) is 011343 - 12 - used to achieve a higher final température of theworking means in conjunction with heating in theabsorber of the collector with a relatively low outlay.The principles of optical concentration, translucent 5 insulation and through flow of the translucentinsulation can be very effectively combined for thispurpose.

The co-operation of a nonproblematical accumulator madefrom cost effective materials even permits the seasonal 10 storage of the insolation over several months, givenappropriate dimensioning. A cost effective individual solution, for example thesupplying of a remote village or a hospital, is therebyrendered possible. 15

Principle of the cycle used

The following discussion, related to spécifie applications, makes it easier to understand theformation of the température field in the working 20 volume, for example in the case of the use of only oneheat exchanger, and the sequence of an overall cycle,z together with the problems on which the object is based. 25 Application of the principle of the invention

The apparatus represented in Figure 1 can operate, inter alia, as a thermal gas compressor (withthe integrated action as a prime mover), and because ofthe simple design and the relatively simple possible 30 theoretical description of the cycle, forms a goodstarting point for understanding the more complexmachines, apparatuses or methods likewise based on theprinciple of the invention. 35 Design A working volume filled with gas as working fluid is largely enclosed by a working cylinder as * 13 · 011343 pressure vessel 1, a slidingly sealed piston 2, andinlet and outlet valves 3 and 4, respectively.

Moving in this working volume against the cylinder wall5 in a slidingly sealed fashion is a frame 6 on which a5 heat exchanger 7 and a regenerator 8, of invariablestructure or size,. are fitted such that they must beflowed through by the gas.

Sprung spacers 9 form between this regenerator 8 and areversibly contraçting and expanding structure 11,10 acting as a regenerator, which is also surrounded by abellows 10 and consists of a fine (40 - 80 ppi) foamplastic or approaches the latter in terms ofhomogeneity or interspaces (for example a plurality oflayers, juxtaposed perpendicular to the flow direction,15 made from embossed or curved métal fabric) over theentire cylinder surface a flow channèl 12 through whichthe gas can pass to the ventilator 14 past thestructure 11 through the opened outlet valve 4 of theworking volume and a part 13 of the pipeline System. 20 This gas. can flow from the ventilator through a part 15of the pipeline System and a regenerator 16, which is// to be flowed through, into a standby space 17 which issurrounded by a bellows.

After heating in a (countercurrent) heat exchanger 18,25 the gas can pass through the inlet valves 3 into theworking volume from the ventilator 14 or from thisstandby space 17 through a part of the pipeline System 19. A pressure tank 20 is connected to the pipeline System• 30 at 13 upstream of the ventilator (turbine) 14 in order to buffer the pressure fluctuation.

The piston 2 and the frame 6 are moved periodically byhydraulic pistons 21, 22, 23 as characterized in Figure4, Figure 5, Figure 6 or the associated description of35 the cycle.

The orientation of the piston 2 with reference to thestroke direction is stabilized by the hydrauliccylinders 21 and 22. 011343

The driving tube 24 of the frame 6 is guidedout of the working volume through seals in the strokedirection by the piston 2. Running in this driving tubeare two tubes for the cooling water which are sealed5 against the inner wall of the driving tube such that nogas exchange with a disturbing influence on the cyclecan take place between the working volume andsurroundings.

Movable hoses 25, 26 connect these tubes to fixed10 connections 27, 28 of a cooled water réservoir, withthe resuit that the cooling water can circulate in a closed circuit.

The liquid in the heat exchanger 7 should always be ata lower pressure by comparison with the working volume,15 so that no liquid can be forced into the workingvolume, something which could lead to dangerous, suddendevelopment of steam - instead, the liquid in the heatexchanger is displaced by inflowing working fluid.

If the hot gas which is to be cooled is introduced20 directly at 19 into the pipeline System of theapparatus for transferring entropy (compare Figure 1),7 and extracted again at 15, the losses and thestructural outlay of the heat exchanger 18 can beeliminated. 25 The hydraulic pistons 21, 22 and 23 exchange mechanicalpower via a controlled valve System 29 of the controlSystem via a hydraulic pump 30 with a flywheel 31 and acomponent 32 acting as electric motor and/or generator.Working fluid can be exchanged from the part of the 30 pipeline System 19 to the flow channel 12 through avalve 33, optionally driven by a ventilator 34 or notthrough a further valve 35.

The valve 33 initially remains closed.

The acceptable, simplifying assumption is made below35 that, as an idéal gas, the working fluid always has thetempérature Tk in the coolest partial volume, that_isto say only isothermal processes proceed there. 5 10 15

Determining the maximum possible output of work by amethod according to the invention, and an apparatusaccording to the invention in the case of which a gasquantity of mass nu can be cooled over a températureintégral from Ti to T2 by coupling to a cycle.

The thermal energy dQ = nu * cp * dT [al] isoutput during cooling of the gas from T + dT to T. Ifthis thermal energy is absorbed isothermally at thetempérature T by a cycle cooled at Tk, the work of atmost dW = η * dQ [a2]; η - 1 - Tk/T: Carnot efficiency [a3]can therefore be·performed. the work Of/ y \

Consequently «'(T,) Q(T,) J J n.dQ[<aj[eii)} r(Tt)

OW 1- \\ Λ can be performed during cooling of the gas from Tx to T2. / 20 25 30 W can be denoted [according to Stephan, Karl:Thermodynamik: Grundlagen und technische Anwendungen;Band 1 Einstoffsysteme [Thermodynamics : Principles andtechnical applications; Volume Γ Unary Systems], 14thEd.; 1992 Springer-Verlag, page 177 ff] as the exergyof the thermal energy which has been extracted from thegas during cooling from Tx to T2 when the codertempérature Tk is equated to the ambient température Tu.

Page 185: Exergy: - L„ =

The hatched area under the curve of tJcctiçj (T) inFigure 2 is proportional to this work W.

In this case, the cycle is fed the thermal enérgy Q =du * cp * (Τχ-Τ2) .

This results in:

011343 for the overall efficiency of this cycle.

If the thermal energy is extracted isothermally from the gas by thermal contact with four idéal heatexchangers at températures Τι.25, Τχ.5, Τι.75, T2 (cf. 5 Figure 3), the exergy shown above is reduced by W_ tothe maximum useful energy W.

This is represented in Figure 3. The formai descriptionand the interprétation follow from the comparison withthose relating to Figure 2. 10

Cycle traversed by the gas in the apparatus relating toFigure 1.

The cycle of movements is determined by thecontrol System and represented roughly in Figure 4, 15 Figure 5, Figure 6 I in a satisfactory fashion for thefollowing analysis.

On the assumption - .confirmed later in more detail -that in the equilibrium operating State the regeneratorSystem 11 has a température profile whose mean 20 température T,», is substantially above the coder température Tk/ the profile of the mean température inz the working volume Tm(t) is yielded immediately therefrom, being represented qualitatively in Figure 4,

Figure 5, Figure 6 II. Because of the standby space 17, 25 the pressure Po in the part of the pipeline System 19upstream on the inlet valves corresponds to atmosphericpressure.

The ventilator 14 is to operate such that thepressure Pi is changed only slightly relative to the 30 differential pressure P1-P2 in the space 13 of thepipeline System adjoining the outlet valve 4.

The valves 3 and 4 are opened or closed by the (flow)pressure of the gas.

The pressure is increased during the corresponding 35 réduction in the working volume from Va to Vb by the movement of the piston 2 in the time period a-b-c, since the inlet and outlet valves 3 and 4, respectively, are closed because of the pressure P(t) - 17 - 011343 in the working volume, which is higher relative to Pobut lower relative to Px.

In the case of the assumed isothermal compression inthe time period a-b-c, the cool gas in the working5 volume at the température Ί\ outputs the thermal energy Q^^PnC^JdV to the coder. y.

In this time period, the control System must perform atthe piston the work of Wabc = -0,^.

This work Wabc corresponds to an area illustrated in a 10 hatched fashion in Figure 7.

In the time period c-d-e, the coolest partialvolume becomes smaller in conjunction with a constantworking volume through a displacement of the frame 6with the cooler 7 and regenerator 8, and this leads to 15 a rise in the mean température of the gas in theworking volume. As " soon as the pressure P(t) in theworking volume rises at the start of this time periodsomewhat above the pressure Pi on the other side of theoutlet valve 4, this valve is opened and the expansion 20 of the gas, which. is associated with the rise in themean température, has the effect that a gas quantity ofmass nu flows out from the working volume through theoutlet valve, is expanded adiabatically in theventilator 14 and in the process perforais the work WU3e, 25 which corresponds to an area in Figure 7.

It holds that: «s 30 Note: T2 is yielded independently of nu for a givenpressure ratio Pi/Po, whereWU3a — Cp * nu * (Ti — T2) * Tjtot·

Each volume V can be divided into subvolumesVlz where by an appropriate, possibly very small - 18 - 5 011 343 division/ such that the following may be set down forVi without effectively falsifying the thermodynamicdescription: I KB i 10 kB: Boltzmann's constant; Tt: température in Vx; Ni:number of gas molécules in Vt.

Mathematical fouridation:

Because of the thermal conduction, acontinuously différentiable température field can beassumed, cf. Riemann intégrais.

It then holds in general that:

15 / 20

Number of the gas molécules exchanged perperiod with the working volume: &amp;N=N-H =£-« ï^rï—-^r=-d‘r' *. i(r)

Note: the letters in the index, for example c in Ncdénoté an instant of the cycle as defined in Figure 4,Figure 5, Figure 6. Détermination of the mass of the exchanged gas quantity1 /3« *, > Tc(r) nie : mass of the gas in the workinginstant c it holds for the time period c-d-e that: volume at the 25 f —-—d3rk Tt(r) f —-—d3rk Tc(r)

The working volume is enlarged by the piston movementin the time period e-f-g.

In this case, the gas is not to flow relative to theheat transfer surfaces which are necessarily active forthe thermodynamic cycle. 30 • 1? - 5 011343 10 15

Since in this time period the gas in the entireworking volume is in direct contact with heat transfersurfaces of high thermal capacities which arenecessarily active for the thermodynamic cycle, and thegas is not moved relative thereto because of theirspécifie movement, this time period of the cycle can bedescribed by an isothermal expansion, the same formulaeholding for the exchanged thermal energy or work as forthe time period a-b-c.

It is therefore possible for this energy to be storedin an oscillating System and to be output again forcompression (for example by an oscillating water côlumnin a U-shaped tube, possibly with a cavity acting as anair spring, as boundary). It holds for the gas quantityadmitted in the time period g-h-a (cf. c-d-e) that: niftgah mftede nia : mass of the gas in the working volume at theinstant a. 20 The température profile, the température field T(r) in the apparatus relating to Figure 1 [lacuna]

In the time period e-f-g,. the largely homogeneousregenerator structure 11 with a thermal capacity whichis very high relative to the gas in the working volume 25 and assumed to be infinité below, largely fills up theentire working volume, and the working volume isexpanded by the displacement of the piston.

Only isothermal processes take place in the workingvolume because of the spécifie movement. 30

Formulation:

Let the working volume be divided into Eequally large partial volumes by E - 1 planes arrangedperpendicular to the stroke. In the idéal case, the 011343 - 20 - température in these planes is constant because of thesymmetry.

The thermal energy Qi = 1/E * Q,f<J is extracted from theregenerator structure 11 in each of the subvolumes by5 the isothermal expansion of the gas. i e[l;£].

During the time period g-h-a, the cooling of the hotgas quantity of mass ioa flowing in through the inletvalves 3 during each period effectively feeds energy tothe regenerator structure 11, since thereby a larger10 gas quantity flows overall from the hot into the colderpart of the regenerator structure 11 than in the caseof the inverse flow direction.

Let the jth one of these subvolumes be bounded (cf.above) by the isothermal planes at températures of Tj15 and Τ1+χ. The gas flow during a period feeds thispartial volume the thermal energy of Qj = mA * CP * (Tj - Tj+J .

It must hold for the formation of an operating state inequilibrium that: 20 Qj = niA * Cp * (Tj - Tj+i) = Qi = 1/E * Qefg A linear température profile in the stroke direction / for T(r) results from (Tj - Tj+1) = (m* * cP * E)"1 * Q.fg.

Achieving a larger température différence Tx - T2 when25 the apparatus characterized in Figure 1 is used as a thermal gas compressor

If the aim in a System is to achieve largertempérature différences in the gas admitted to andoutput from the working volume, a gas quantity of mass30 mH must flow from the part of the pipeline System 15into the flow channel 12 through a further inlet valve35 in the time period g-h-a.

That is to say, the valve 33 is open, and theventilator 34 can remain stationary. 35 With Ti, T2, Po unchanged, Px can be selected such thatthe gas quantity drawn in overall remains constant,that is to say this measure reduces by πίκ the mass m* of - 21 - 011343 the gas which is drawn in in a hot State and forced outat a lower température and higher pressure.

Less thermal energy is therefore exchanged during aperiod with the regenerator System 11. 5 The pressure ratio Pi/P0 must therefore be lower in thiscase.

With Ti, Plz Po unchanged, the same quantity ofthermal energy is fed during a period to theregenerator System 11 only whenever the exchanged gas10 quantity is more intensely cooled. A larger température différence Tx - T2 can thus beachieved given the same pressure ratio Pi/Po.

Given a constant pressure ratio Pi/P0, the températureT2 can be stabilized rèlatively simply by a simple15 thermostat control for the inlet valve 35.

The inlet valve 35 is opened in this case only wheneverthe gas (just) exceeds the stipulated température at15.

If appropriate, it is also sufficient to reduce the20 flow résistance in the région of the inlet valve 35 inconjunction with rising température of the gas. àt 15, // for example by a baffle, controlled by a bimetal, whichchanges the cross section for the flow. 25 Achieving a smaller température différence Tx - T2 whenthe apparatus characterized in Figure 1 is used as athermal gas compressor

If the aim in the System is to achieve a higherpressure ratio Pi/P0 during the cooling of the exchanged30 gas by a spécifie température différence, the gasquantity of mass me must be sucked from the flowchannel 12 through a further (driven) outlet valve 35in the time period g-h-a with the aid of a ventilator34 which, in the idéal case, uses adjustable éléments35 to apply the pressure différence, which is smallrelative to Pi - Po, required for this purpose only inthis time period. This gas quantity is fed to the space15 of the pipeline System. - 22 - 01 1 34 3

That is to say open valve 33.

If four such working volumes operate with a phase shiftof 90°, a commercially available ventilator can rununiformly, that is to say only the outlet valves 35 5 need be controlled with some expenditure of force andenergy.

Consequently, with Tiz T2, Po unchanged, the exchangedand cooled gas quantity m* is enlarged by ma, and alarger quantity of thermal energy is fed to the 10 regenerator System 11 during a period.

This more substantiel thermal energy is partiallyextracted again from the regenerator System 11 in thetime period e-f-g during the effectively isothermalexpansion of the gas from Pi to Po, it being possible to 15 achieve a higher pressure ratio Pi/Po, resulting in moreenergy being converted overall per period, in whichcase the thermal energy exchanged overall at theregenerator 8 or at the regenerator System 11, and alsothe thermal losses associated therewith are increased 20 in a far lower ratio. A better efficiency is thereby achieved overall. 7 If the mass flow through the adjustable ventilator canbe set in 3 stages (out, average, large), and the stageof large can always be switched on by a thermostat 25 whenever à spécifie température is undershot, thetempérature T2 can thereby be stabilized sufficientlyat a value with a relative low outlay.

Use of the apparatus characterized in Figure 1 as a 30 refrigérating machine

The apparatus represented in Figure 1 can also be operated as a refrigerating machine which cools agas quantity over a large température interval.

For this puxpose, the ventilator (turbine) 14 then 35 driven must force the gas from the part of the pipeline

System 19 at the pressure Po into the part 13 at Px. _

The flow direction of the gas is reversed (in the working volume overall), and the design of the - 07 - 011343 apparatus and the sequence of movements are maintainedas represented in Figure 1 and Figure 4, Figure 5,Figure 6, respectively.

The outlet valve 4 becomes an inlet valve by virtue of5 the fact that it is held open against the flow pressurein the tinte period c-d-e, for exantple by an engagingspring connected to the control System, in conjonction with an unchanged stop direction.

The gas then flowing in at the pressure Pi outputs 10 thermal energy to the regenerator System 11 uponcooling.

During the effectively isothermal expansion of the gas(as above in the case of the gas compressor; primemovers) from Pi to Po, thermal energy is extracted from15 the regenerator System during the time period e-f-g. Asshown above in the case of the description of the primemover, with the refrigerating machine, as well, the co-opération of the partial processes in the time periodsc-d-e and e-f-g forms in the regenerator structure 11 a20 température field T(r) which is linear in the strokedirection and whose mean température Tm is below thecoder température Tk in the case of the refrigeratingmachine. (Temporal development of Tm(t) in Figure 4,Figure S, Figure 6: substitute max. T„(t) with min.25 T(t)).

As a resuit, the mean température in the working volumeis increased in the time period g-h-a upon telescopingof the regenerator System 11.

The inlet valves of the prime mover 3 can act as outlet 30 valves in the case of the refrigerating machine whenthey are held open against the flow pressure in thistime period g-h-a, for example by an engaging springconnected to the control System, in conjunction with anunchanged stop direction, and because of the increase 35 in the mean température in the constant working volume, gas flows out at a constant pressure Po into the .part of the pipeline System 19. 011343 • 24 -

Before this gas is compressée! anew by the ventilator (turbine) z it absorbs in the heat exchanger 18 the thermal energy originating from the cooling of the other gas flow. 5 When the gas to be cooled is introduced directly into the pipeline System of the refrigerating machine at 15(cf. Figure 1) and extracted again at 19, the lossesand the design outlay of the heat exchanger 18 can beeliminated. · 10 In the time period c-d-e, the mean température of thegas in the working volume is lowered in conjunctionwith a constant working volume by the expansion of theregenerator System 11, which, because of the fact thatthe valve 4 is held open, leads in conjunction with a 15 constant pressure Pi to an inflow of warmer gas,additional feeding of thermal energy to the regeneratorstructure 11, and the closure of the cycle.

Achieving a larger température différence Tx - T2 when 20 the apparatus characterized in Figure 1 is used as athermal refrigerating machine r,/ The apparatus represented in Figure 1 and already described as a prime mover can, as alreadylargely represented above, also be operated as a 25 refrigerating machine. As in the case of the primemover, given an open valve 33 and stationary ventilator34, a larger température différence of the gasquantity, absorbed and output by the working volume, ofmass mA can be achieved when a gas quantity of mass mn 30 flows out. in the time period g-h-a into the space 15through the valve 35, which acts in this case inconjunction with the same stop as an outlet valve whichis held open by the control System against the flowpressure in this time period g-h-a. Air is also forced 35 through the turbine 14 and the valve 4 into the working volume in the same time period g-h-a.

With Ti, px, Po unchanged, the regenerator system 11 is fed an equally large quantity of thermal energy during 011343 - 25 - a period only whenever the gas is more intenselycooled. It is thereby possible to achieve a largetempérature différence Tx - T2 in conjunction with thesame pressure ratio Ρχ/Ρ0. 5 Given a constant pressure ratio Ρχ/Ρ0, the températureT2 can be stabilized relatively easily by a simplethermostat control for the outlet valve 35.

The outlet valve 35 is opened in this case onlywhenever the gas (just) exceeds the stipulated10 température at 19.

Achieving a smaller température différence Tx - T2 whenthe apparatus characterized in Figure 1 is used as athermal refrigerating machine 15 The prime mover represented in Figure 1 can, as already represented above, also be operated as arefrigerating machine. If, as in the case of the primemover, the aim is also to operate with a largerpressure différence Ρχ - Po in the case of the 20 refrigerating machine for a spécifie cooling, this canbe achieved when the gas quantity of mass ma is blownwith the aid of a ventilator 34 from the space 15 intothe flow channel 12 through a further (driven) inletvalve 35 in the time period g-h-a. - 25 As a résult, in the operating . State the regeneratorSystem 11 is fed a correspondingly larger quantity ofthermal energy by comparison with operation without thevalve 35, and correspondingly more thermal energy isextracted again in the case of the isothermal expansion 30 in the time period e-f-g by an expansion with a higherpressure ratio Ρχ/Ρο·

The advantages of these measures, or the control of thetempérature T2 are largely similar to the case of thecorrespondingly operated prime mover relating to Figure35 1.

Action as a heat pump - 26 - 011345

When, by virtue of the reversai of ail thedirections of movement, the control System runs in thecase of the refrigerating machines described above suchthat the moving parts change their position in 5 accordance with Figure 4, Figure 5, Figure 6 in thereversed sequence h-g-f-e-d-c-b-a, and the ventilatoroperating directions remain unchanged relative toFigure 1, these apparatuses act as heat pumps whichinstead of · cooling the gas blown in heat it over 10 comparable température intervals in conjunction withcomparable pressure ratios.

The cycle for the case of the use of an apparatusaccording to Figure 1 as a heat pump 15 Thermal energy is fed to the regenerator System 11 in the time period g-f-e in the case of theisothermal compression (with valves closed) of the gasfrom Po to Pi. Upon telescoping of the regeneratorSystem 11 in the time period e-d-c, gas ât the 20 température TH is admitted by the turbine from the working volume at the pressure Pi through the valve 4, <z which is being held open, since the mean température is lowered.

In the time period c-b-a, the gas is expanded to the 25 pressure Po with the valves closed, and so thermal energy is extracted from the heat exchanger at thetempérature Tic. In the time period a-h-g, the meantempérature in the working volume is increased with theexpansion of the regenerator System 11, and gas at the 30 température Tx is output through the valves 3 at Po.

If, simultaneously with this, gas with the températureof approximately TH is pushed by the ventilator 34 outof the space 15 into the flow channel 12 through thevalve 35, the différence in the températures TH - Tx is 35 reduced in conjunction with the same pressure ratioPx/Po.

As in the case of the prime mover, this measure ofmaking a change leads to a larger conversion of • 27 - 011343 mechanical energy in conjunction with thermal losses ofapproximately the same magnitude. If gas passes fromthe working volume into the space 15 of the pipelineSystem through the valve 35 controlled via the gas5 température at 15 in the time period a-h-g, it isthereby possible to achieve a larger températuredifférence (cf. refrigerating machine or prime movercorresponding to Figure 1).

Fresh air can be filtered and heated with this10 heat pump.

The regenerators in the working volume act as filters.The thermal energy fed to the fresh air originatespartly from a colder heat réservoir such as the ambientair or the groundwater. 15 The thermal pump sketched can be designed such that theair virtually does not corne into contact withlubricants, and that the f ilters can be changed easilyupon contamination. 20 Hot gas + cool gas yields warm gas at a higher pressure•In order to be able to admit two gas quantifiesof masses miz m2 at thé températures Tx and T2zrespectively, into a working volume, and to output themagain at a higher pressure at a température T3 situated 25 between Ti and T2z it is necessary to make the followingmodifications by comparison with the entropy transformers represented in Figure 1:

Fitted on the piston 2 are valves of the type 3through which the cold gas can flow into the working30 volume from a buffer space, formed by the cylinder 1,which is large relative to the change in the workingvolume. A regenerator System similar to 11 is arrangedbetween these valves and the driven fiat frame 6 of theregenerator 8. The heat exchanger 7 can be eliminated.35 The sequence of movements, and the change in the meantempérature Tm(t), or the pressure in the workingvolume P(t) correspond nevertheless largely to thequalitative représentations in Figure 4, Figure 5, - 28 -

I 011343

Figure 6. Gas at the température Tx or T2, respectivelyzis drawn in through the respective valves in the timeperiod g-h-a. Given an appropriate setting of the ratioof the masses of the drawn in gas quantities mx (Tx) and 5 m2, a linear température profile is yielded in thestroke direction. This would hâve to prove idéal forthe efficiency.

The gas quantities flowing into the working volume mustbe appropriately controlled by valves. 10 If the cooler gas is to expérience only a slighttempérature change, as described above gas must besucked from the working volume by a ventilator througha further valve (cf. 35) during this inflow process.Arriving at the flow channel 12 is a further flow 15 channel, arranged with mirror symmetry relative to theregenerator 8, for the gas flowing from the workingvolume. Respectively adjoining each of these flowchannels are the valves 4 and 35 or correspondingvalves, by means of which it is possible to vary the 20 température intervals for the exchanged gas quantitiesover wide ranges (cf. Figures lb, le).

Overall, this entropy transformer is possibly easier toconstruct, since there is no need for a heat exchanger(for example an automatic cooler). 25 Moreover, steam cannot suddenly develop because ofescaped cooling water.

As already shown above in the case of the gascompressor, this design can also be operated such thatlukewarm gas at a higher pressure is forced by a 30 turbine into the working volume and, as a resuit, theflow direction, but not the periodic sequence ofmovement (cf. Figure 4, Figure 5, Figure 6) is changed,and hot and cold gas flow out from the working volumeat a lower pressure.

Combination of a refrigerating machine and prime mover

If hot gas and cool gas or cooling water at the température Tk are available, gas can be cooled by an 35 - 29 - 011343 entropy transformer with 2 working volumes below thecooling water température Tk.

In principle, for this purpose in the case of one ofthe refrigerating machines described above the driven5 ventilator 14 is replaced by one of the apparatusesdescribed above and acting as a gas compressor, the hotgas being accepted by the working volume, which can beassigned to the gas compressor, and being output in thecase of higher pressure through the outlet valve 4 of10 this working volume into a space of the pipeline Systemto which a buffering pressure vessel can be connected,and from which the gas, possibly after prior cooling toapproximately Tk, flows through the valve 4 acting asinlet valve, into the working volume which can be15 assigned to the refrigerating machine.

The gas, cooled to below Tk, flows out from thisworking volume through the valves 3 and, possibly, 35.(As represented above), the periodic flow through thevalves 35 of the two working volumes can be set20 appropriately to tune pressure and température différences.

If the movements represented in Figure 4, Figure 5,Figure 6 I proceed simultaneously in a working volume,the buffering pressure vessel can be of smaller25 dimension, or be eliminated.

It is also interesting to use this combination as aheat pump for liquid.

Further interesting combinations serve to increase thecalorific value to a value of above 1. 30 Thus, one hot and cold gas quantity each are admittedfrom a first working volume, as described above, andoutput again at higher pressure as a cool gas quantityand accepted by a second working volume, which outputsit again as a warm gas quantity at the output pressure.35 In this process, the liquid of a heat exchanger. wascooled in the second working volume, or an addi-tionalgas quantity was cooled. 011345 • 30 -

Constant working volume

Function described: part of a gas compressor(prime mover)

As part of a prime mover, for example, the working5 volume, represented in Figure 8, Figure 9 or Figure 10,of an entropy transformer has two différences décisivefor the thermodynamics, by comparison with that shown in Figure 1 or Figure 4, Figure 5, Figure 6:

Firstly, the size of the working volume is not changed. 10 Secondly, instead of the relatively homogeneousregenerator System 11, represented in Figure 1, thereare active in the working volumes relating to Figure 8,Figure 9 or Figure 10 four discrète, rigidlyconstructed regenerators 36, 37, 38, 39 on which, as on 15 the two further regenerators 40 and 41, four tubes eachare fastened which are respectively part of one of thefour concentric arrangements of tubes 42 of the controlSystem.

These components 36 - 41 and the frame with the heat

20 exchanger 43 acting as a coder are sealed with V2A / sealing brushes on bronze cylinder wall métal sheets44, as also the tubes for the heat exchanger liquid 45,46 such that they are flowed through between the sealand cylinder wall in the operating state by the working 25 means with a minimum flow loss (below 10%) .

The periodic sequence of movements of these componentsis represented qualitatively in Figure 9 1 or Figure 10I with the désignations H: for stroke and t: for time.The regenerators are constructed from a lower V2A 30 perforated sheet with as small as possible a métalsurface fraction and having U profiles made from V2Awhich are welded on for reinforcement and are parallelto the perforated sheet, and into which métal fibres(centroid of the diameter at 40 micromètres) are pushed 35 which are sheathed with V2A fabric (wire diameter approximately 0.1 mm) and are clamped and enclosed by a further perforated sheet. - 31 - 011343

The two perforated sheets are held together by a wirewinding at the point where the perforated sheets hâvebeen deformed such that the outer surfaces of theseregenerators hâve no local élévation despite the wire5 winding.

At the edge, the perforated sheet merges into a sheetwithout perforations/ as a resuit of which the sealsare held and sealed relative to the métal fibres suchthat the latter are flowed through. Otherwisez a10 working volume filled with gas as working fluid islargely enclosed by a pressure housing 47, and inletand outlet valves 48 and 49, respectively, in a fashiônsimilar to the prime mover as in Figure lz Figure 4,Figure 5, Figure 6. The gas can flow into the partial15 volume between the çylinder cover and the regenerator36 through the inlet valves from a space of thepipeline System which corresponds to 15 in Figure lzand flow out from a space between the regenerators 39and 40 through a tube 50 in which a tube 45 with the20 line 46 for the heat exchanger liquid runsconcentrically and ih a permanently connected fashion, / and is inserted periodicallyz in a fashion sealed withbrushes 52, into one of the tubes 51 which bound theworking volume and are not periodically moved. From25 this tube 51, the gas can pâss through the outletvalves 49 into a space of the gas pipeline System whichcorresponds to that in Figure 113.

In the case of the periodic movement, represented inFigure 9 Iz of the éléments 36-41, 43, the latter are30 guided in the stroke direction in the middle of theworking çylinder on a stationary tube. Fitted on eachof the 6 regenerators 36-40, 41, are four carriages 53which can be moved only in the direction of the surfacecentroid of the regenerator and on which of each of the35 four concentric tube arrangements 42 one tube isfastened with a bayonet lock 54 such that the carriages53 also serve as a guide for the inner tube. - 32 - 011343

In each case two tubes of the tube arrangements 42which bear against one another hâve a larger lengthdifférence and stroke différence (cf. Figure 9 I), thetube with the smaller diameter being longer. 5 The tubes which are movably connected at one end to theregenerators 36-40 by the carriages 53 are connected atthe other end via in each case two holders, situatedopposite one another relative to the tube axis, forbearings 55 with the aid of two levers 56 which are 10 movably connected at the other end to in each case twolevers 57 which are oppositely situated per tubearrangement 42 with reference to the tube axis and onwhich the point of action 58 for the movable connectionis removed the further from the tube axis in a 15 plurality of uniform spacings the larger the tubediameter is.

The tube connected at one end to the regenerator 41 andsituated entirely inside in the tube arrangement 42 isconnected at the other end to a short length of tube 20 60, via two rods 59 guided past laterally at the levers of the other tubes, which tube 60 can slide on the tube r fastened on the regenerator 36, and to which, asdescribed above, there are likewise movably connectedtwo levers of the type 56 which are connected to the 25 levers 57 at the other end with the greatest distancefrom the tube axis.

The entire moving structure of 55 - 60 is also surrounded tightly in the operating State by a housing61 such that as little dead space as possible remains, 30 since the pressure is periodically changed inside thishousing, which is connected to the working volume, thatis to say this housing is part of the pressurecontainer.

Since in the case of the use of automatic coolers and 35 the space requirement for the frame carrying them, the surface of the heat exchangers which is flowed throûgh is decisively smaller than the surface in the working volume perpendicular to the stroke, the sequence of •JJ - 011343 movements represented in Figure 9 I was selected, noregenerator being against the heat exchanger structure43 in the time period a-b-c and, above ail, theautomatic coolers being flowed through by the gas. 5 In the time period e-f-g, the regenerators 40 and 41bear tightly against the heat exchanger structure,whose large-volume interspaces are filled with wood (orFRP) in a fashion capable of being flowed through suchthat the regenerators are flowed through as uniformly10 as possible. In this case, in the heat exchangerstructure 43 the gas flowing past by the automaticcooler must overcome a decidedly larger flow résistancethan that flowing through an automatic cooler, so thatthe automatic cooler is flowed through by gas in the15 time period a-b-c in conjunction with an only slightbypass gas. flow. In the case of the regenerator 39, thedisplaceable carriage 53 is connected to the frame ofthe heat exchanger structure 43 at fixed spacings withthe aid of screws and spacer tubes (118) , which are20 guided. by the carriages of the regenerator 40. Alsoconnected to this frame are the tubes 45, inside whichthe Unes 46 for the heat exchanger liquid arearranged. These tubes are led out of the working volumeand connected to a frame 64 by tubes 62, which also25 form part of the pressure housing, and seals 63.

Two tubes 65, which are fastened to this frame in aflexurally stiff fashion, run in the stroke directionand are arranged opposite one another in the strokedirection with reference to the central axis of the30 working volume, · are guided in parallel in the strokedirection by in each case two sliding bushes 66, whichare fastened on a tube 67 running in parallel andpermanently connected to the pressure housing.

Tension springs 68, which are loaded between the upper 35 ends of the permanently standing tube 67 and the lower end of the tube 65 fastened on the moving frame 64, partially compensate the weight force of the moving structure. - 34 - 011343

Two connecting rods 69 are fastened movably on theframe 64 such that the bearings are arranged situatedopposite in the stroke direction with respect to thecentral axis of the working volume. The other ends of 5 these connecting rods 69 are fastened in each case tochains 70 with a bearing axis parallel to the chainstuds.

The bearing fastened on the chain 70 is formedby two identical dises 71 with two bores 72 each, the 10 dises 71 engaging in the bore 73 of the connecting rod69 from both s ides, surrounding the bearing rod. 69 withtheir collar 74, and being fastened with the aid of thebolts of the chain joint 75 of a three-fold chain onthe two-fold chain 70 and installed in it. 15 In each case one of the chains 70 runs over twosprockets 76, which are mounted unilaterally such thatthe parallel bearing axes are arranged perpendicular toand with a displacement symmetry in the strokedirection, and the connecting rod does not hit as the 20 chain revolves. Fastened on the same spindle on thelower of these sprockets is â further sprocket 77 withan adjustable relative angle, which is coupled via afurther chain 78 to a sprocket 79 which is connected toone of two two-fold sprockets 80, mounted on onëaxis, 25 on a spindle with an adjustable relative phase, overwhich a three-fold roller chain 81 runs such that itprojects over the sprocket in the direction of thechain stud on the side on which no spindle leads to thesprocket. 30 The pitches of the sprockets 77 and -79, as well as 80and 76 are of the same size in each case, and thechains 81 and 70 are of equal length. A chain link with rollers is removed from theroller chain, and in return a lever 82 is inserted 35 between two métal sheets 83, originating from the chain, with in each case two holes together with. a singly drilled dise 84 through two chain joints (plug- in links with spring locks) 85 and further chain links 011343 = 35 ® 86 at the point where there is no contact with thesprockets because of the overhang of a Chain.

At another point of the chain in the sametrack, a further lever 87 is rotatably fastened in the5 same way at one end and offset such that the other endis rotatably fastened on a bearing 88 between the ends,mounted on the same axis, of the other lever 82 and ofthe connecting rod 89.

The spacing of the lever axes of the levers 87, 82 10 corresponds to the pitch of the two-fold sprockets 79or 76.

The connecting rod 89 is fastened mounted in arotatable fashion on the other end on a further frame90. 15 Fastened on the frame 90 are four tubes 91 which run inthe stroke direction and dip through seals 92 intotubes which belong to the pressure housing and areconnected at the other ends to the carriages 53 of theupper most regenerator 36. The axes of the lower 20 sprockets 76 which are the outer ones in the strokedirection with reference to the central axis of theworking volume, are so long that sufficient spaceremains to be able to fasten on the other mounted end afurther sprocket 94 which ï"s~cônnëcted to a chain 95, 25 96, guided thereover, with a sprocket 97 which is fastened on a spindle which forms part of the electricgeared motor (which is fitted with the additionalflywheel on the motor axis).

So that the abovementioned far-reaching mirror symmetry 30 of the chain drive also holds for the direction ofrévolution of the sprockets, a chain is guided by 2chain rollers 98 such that the sprockets 97 and 94engage in the links of the chain 95 from differentsides. 35 In order to be able to achieve the movements, represented qualitatively in Figure 91, in conjunetion with acceptable accélérations, the spacings of the bearings of the levers 82, 87 must be suitably 011343 - 36 selected, and the chains must be appropriately clampedand suitably adjusted by setting the phase of thesprockets 77 and 76 or 79 and 80, which are fastened onone spindle. 5 With reference to the direction of révolution, as well,the overall chain bearing largely has a mirror symmetrywith reference to the plane in which the central axisin the stroke direction of the working volume and oneparallel to the bearing spindles of the sprockets lie. 10 This movement is characterized in that the regenerators36 - 40 largely bear against one another in a timeperiod a-b-c of the cycle, and is flowed through fromthe cooler in the case of the movement of a portion ofthe gas in the working volume. 15 The conduit 46 penetratés the fastening of the tube 45on the lower stroke frame 90, is sealed there againstthe tube 45 and fastened by a screw running in a spacertube présent there such that for mounting purposes itcan be pushed into the tube 45 by approximately 10 cm. 20 The short connecting hose from the conduit to theautomatic cooler stub can be mounted in this way. f s

Pushed over each of the tube lengths 45, inwhich the conduit lengths 46 for the heat exchangerliquid (water with ahtifreeze agent) run, in a closely 25 fitting fashion on the end in the working volume is atube sleeve 99 on which the seals 100 of theregenerator 40 slide and on which there are permanentlywelded small métal parts 101 with holes in the strokedirection to which it is screwed to the air guide tube 30 50 with the aid of permanently welded nuts 120.

At the common end, the tube length 45 and the tubesleeve 99 are screwed in the radial direction to amétal piece 119 to which the frame which carries theheat exchanger is screwed. 35 As a resuit, during mounting the tube lengths 45, 46 can be pushed into the pressure vessel from outside through seals 63. - 37 - 011343

The periodically moved rigid pipeline System for theheat exchanger liquid of a heat exchanger has upstreamand downstream of the heat exchanger in the throughflow direction two tubes 102, 103, running in the 5 stroke direction, which in each case dip from aboveinto a separate standing vessel 104, 105 with heat exchanger liquid, a pump 106 pumping the heat exchangerliquid from the heat exchanger in the working volumeinto the vessel 105, from where it flows into the other10 vessel 104 after outputting heat in a further idle heatexchanger (for example cooled by groundwater).

The liquid level of these vessels with an openingshould, other than as represented in Figure 8, be belowthe working Volume so that in the event of a leak or15 hole in the liquid circuit there is no relatively largeaccumulation of liquid in the working volume, whichcould lead to a dangerous sudden development of s team,but that gas is drawn into the heat exchanger liquidconduit System, and the pipeline System is thereby20 emptied.

In order to be able to achieve this emptyingcompletely, a thin hose (garden hose) is pushed intothe tube 102 from the vessel 104 as far as the deepestpoint of the heat exchanger in the working volume. 25 The thermal expansion of the material becomes a problemin the case of the targeted order of magnitude (100litres working volume) of the machine. It is counteredin that the pressure vessel 47 itself remains largelyat ambient température and is insulated in a space30 filling fashion against the hot interior (for examplewith glass foam 107).

The cylinder wall 44 in the stroke direction is thenformed from two layers of sheet-metal strips, arrangedoffset, of width 20 - 30 cm, the approximately 3 - 5 mm35 wide joints running in the stroke direction.

The surfaces of the pressure housing, which" arearranged largely perpendicular to the stroke direction,are likewise largely insulated in a space-filling - 38 - 011343 fashion, likewise with glass foam 107, for exemple,against the interior, which is held by a reinforcedfiat métal sheet. At the perforations, of the élémentsof the control System, for example, this métal sheet 5 must be eut out generously in the direction of itssurface centroid and hâve an appropriate spacing at theedge in relation to the adjoining one.

The valves 48 and/or 49 are opened or held open via aBowden cable or a linkage by a lever which is pressed 10 with a roller onto control plates which are fastened onthe chain links of the chains 70 or 81.

In order to be able to open these valves even in thecase of a larger pressure différence and underpressurein the working volume, a valve parallel thereto and 15 having a substantially smaller cross-sectional surfaceis opened in advance by the same drive for the purposeof lowering the pressure différence.

In the partial volume which is delimited from theworking volume only by the regenerator 41, grid planes 20 108, which are to be flowed through by the gas and are arranged perpendicular to the stroke direction, are 7 moved by the control System, as characterized in Figure9 I, such that in relation to this regenerator 41 orthe neighbouring, already moved grid ‘plane, they either 25 keep a spécifie spacing (for example 20% of the totalstroke) or remain as close as possible to the boundarysurface of the pressure vessel.

Largely the same applies to the drive of the gridplanes 109 in the partial volume of the working volume 30 which is delimited only by the regenerator 36. In thecase of this periodic sequence of movements, in theoperating State these grid planes are flowed throughlargely only by gas at constant température, and theformation of eddy flows, which can cause mixing of gas 35 quantifies with the maximum température différences into this partial volume is strongly impeded.

Drive: cf.: Patent Claims 99, 100. - 39 - 011343

Like the working volume in Figure 1, the working volumerepresented in Figure 8 is connected to a pipelineSystem and integrated into the surrounding System.

In the case of the regenerator 39, the5 displaceable carriage 53 is connected at fixed spacingsto the frame of the heat exchanger structure 43 withthe aid of screws and spacer tubes 118, which areguided through the carriage of the regenerator 40.

At the common end, the tube length 45 and the10 tube sleeve 99 are screwed in the radial direction to amétal piece 119 on which the frame which carries theheat exchanger is screwed.

Pushed over each of the tube lengths 45, inwhich the conduit lengths 46 for the heat exchanger15 liquid (water with antifreeze agent) run, in a closelyfitting fashion on the end in the working volume is atube sleeve 99 on which the seals 100 of theregenerator 40 slide and on which there are permanen'tlywelded small métal parts 101 with holes in the stroke20 direction to which it is screwed to the air guide tube50 with the aid of permanently welded'nuts 120. /

Cycle of the gas in the constant working volumerepresented in Figure 8 25 The basic considérations which are undertaken in relation to the System characterized in Figures 1 or3 and used, inter alia, as a gas compressor, also holdfor this System characterized in Figure 8 or Figure 9and acting as a gas compressor. 30 Thus, it may also be assumed for this purpose that inthe equilibrium operating State the regenerators 36 -40 hâve a température profile whose mean température Tm,is substantially above the température Tk of thecooler. 35 The qualitative time profile of the mean température in the working volume TB(t) is yielded therefrom directly and is represented qualitatively in Figure 9 II. 011343 40 -

As shown in Figure 1, the inlet and outletvalves are to be connected to the surrounding Systems,that is to say because of the standby space 17 thepressure Po in the part of the pipeline System upstream 5 of the inlet valves 48 corresponds to atmosphericpressure.

The turbine 14 in Figure 1 is to operate such that thepressure Pi is varied only slightly relative to thepressure différence Pi - Po by the co-operation with an 10 upstream compensating pressure vessel in the space ofthe pipeline System adjoining the outlet valve 13.

The valves 49 and 48 are opened and/or closed by the(flow) pressure of the gas.

In the equilibrium operating state, the gas in the 15 working volume has reached its lowest mean températureTB(t), cf. Figure 9 I, at the instant a.

Directly thereafter, the inlet valve is closed by theflow pressure of gas flowing from the working volume asa conséquence of the raising of the mean gas 20 température Tm in the working volume.

As long as the pressure in the working volume is lower ./ than the pressure Px on the other side of the outletvalve 49, the latter is also closed.

The increase in the mean gas température Tm(t) in the 25 working volume leads to a rise in the pressure in thetime period a-b-c from Po to Pi: P=kt· H'—4-

In this case, thermal energy is output to the cooler bythe compressed gas. 30 At the instant e, the gas in the working volume hasreached the highest mean température Tm(t).

Upon the subséquent lower ing of T„(t) in the time period e-f-g, the outlet valve is closed again by the pressure in the working volume, which is lowered by 35 comparison with Pt. The pressure in the working volume is still too large for an opening of the inlet valves, 011343 - 41 - so that the lowering of Tm(t) leads to a réduction inthe pressure P(t) in the working volume. In this case,thermal energy is taken from the regenerators 37 - 40(cf. Qefg), since the gas flowing through is expanded5 again between two regenerators.

Upon a further increase in Tm(t) in the time period c-d-e, the outlet valve is opened by the somewhat higherpressure in the working volume, and a gas quantity ofmass icia flows out. 10 The maximum mean température of the gas in the working volume is reached at the instant e.

The mass of the gas in the working volume is smaller inthe subséquent time period e-f-.g than in the' timeperiod a-b-c. 15 The pressure différence of Pi - Po is already reachedafter a slight lowering of Tm(t).

Upon the further lowering of Tm(t), the gas quantity ofmass mA of the working volume is admitted through theinlet valve at constant pressure Po until the smallest20 value for Tm(t) is reached again at the instant j = a.The gas quantity which has flowed in is cooled by the f ’ · . output of thermal energy to the regenerators 36 - 40,and upon thorough mixing with cooler gas.

It holds in general that: thermal energy is25 extracted over a complété period from a partial volumedivided off from the working volume by the componentscharacterized in Claim 1 when said partial volume is(considerably) smaller on average during the timeperiod of the pressure rise than during that of the30 pressure drop.

If in the case of this machine ail the valves aresuddenly closed in the operating State of equilibrium,a process proceeds which is very similar to that of aVuilleumier heat pump. In this case, thermal energy is35 extracted from the partial volumes of the workingvolume between the regenerators 36 - 40, and partiallyoutput in the cooler. 011543 • 42 -

This partial cycle drives a second partial cycle whichpumps from the partial volume of the working volume,which is delimited only by the regenerator 41, into thepartial volume which is delimited from the working 5 volume only by the regenerator 36.

This process can be prevented from being set in train inadvertently by a jamming valve, and instancesof destruction owing to overheating can be prevented bymeans of a valve which is controlled by the température 10 of the partial volume at risk and which reduces aconstant pressure in the working volume in anemergency.

If, by means of an appropriately low sélection of thepressure Pi the outlet valve is already opened a small 15 fraction of the time period a-b-c after the instant aat which the lowest mean gas température prevails inthe working volume, the pressure in the working volumeis then increased in this cycle above ail when thepartial volume delimited only by the regenerator 41 and 20 that adjoining the cooler are at their maximum size,and the partial volume delimited only by the / regenerator 36 and the partial volumes between tworegenerators are largely at their minimum size.

The other extreme ratio prevails during dropping of the 25 pressure in the working volume.

As a resuit, with reference to these partial volumesthe thermal energy is turned around by this overallcycle into the other direction than that in the case ofclosed valves (cf. above). 30 The pressure Pi can be selected between these twoextremes such that on average per period no thermalenergy is extracted from or fed to the partial volumeof the working volume, which is delimited only by theregenerator 36, by means of the cycle. 35 The thermal energy which is fed by irréversible phenomena such as the shuttle effect, thermal conduction and the unfavourable efficiency of the regenerator to the partial volume of the working volume - 43 - 01 1 3 Δ which is delimited only by the regenerator 41 isextracted again at this pressure Pi by the spécifiesequence of movements, represented in Figure 9 1, ofthe regenerator 41, and fed to the coder. 5 The sequence of movements characterized in

Figure 10 has the advantage that the flow channels forthe gas exchange are covered only to a small extent bythe moving regenerators, or are better constructed.

By contrast with the représentations in Figure 8, for10 this purpose the lower stroke frame 90 must beconnected to the lowermost regenerator 41.

It is also possible to set the pressure PI for thissequence of movements in the working volume sô as toproduce a similar thermal energy balance for the15 corresponding partial volumes.

Thermal energy is extracted from the partialvolumes of the working volume bëtween in each case twoof the regenerators 36 - 40 by virtue of the fact thatthe gas flowing through is further expanded in the time20 period e-f-g between two regenerators.

Thermal energy is fed to these partial volumes during aperiod by virtue of the fact that on the basis of thegas quantity of mass πια, which is admitted in the hotState into the working volume through the inlet valve25 48 and output through the outlet valves 49 in a coder

State, the regenerators 36 - 39 are flowed through by agas quantity which is larger by this gas quantity ofmass mA when through flow is from the hottest siderather than from the cooler side. 30 in this case, a température profile with a steepergradient in the through flow direction is formed on thecooler Side of one of these regenerators, which areassumed to be homogeneous. Given the assumed uniformquality of the regenerators, more thermal energy is fed 35 to than extracted from one of the above defined partial volumes during the periodic through flow.

The thermal energy output during the cooling of the gas quantity of mass nu which flows periodically in a hot 011343 - 44 -

State into the working volume and out again in a coderState is partially absorbed by the cycles proceeding inparallel between the partial volumes and exhibiting alargely isothermal absorption and output of thermal 5 energy. As a resuit, a linear température profile isformed in the working volume, as represented in generalabove in relation to Figure 4, Figure 5, Figure 6.

As a resuit, the average températures of adjoiningpartial volumes of the working volume between in each 10 case two of the regenerators 36-40, given the same sizeand temporal order of magnitude, exhibit the samedifférence as represented in general above relative toFigure 4, Figure 5, Figure 6.

The maximum amount of work which can be performed in 15 this case is reduced by W_ by comparison with theexergy (Tu = Tk), as explained in relation to Figure 3.Losses at the regenerators 36 - 39 are reduced in partby W_.

Because of the irréversible phenomena such as thermal 20 conduction or the losses of the regenerators, only arelatively low pressure ratio Ρχ/Ρ2 is achieved, and thez gas quantity xn*, must, above ail in the case of anapparatus constructed as in Figure 8, enter the working volume at a température which is higher than Ti. 25 One of the valves 49 in Figure 8 can be used like the valve 35 in Figure 1 in order in conjunctionwith the same ratio of the pressures P1/P0 to achievethe described changes in the température différencesduring cooling or heating of a fraction of the 30 exchanged gas.

Note : A ventilator for drawing in hot air is notnecessarily mandatory, since hot air is drawn into the 35 working volume as soon as the regenerator is moving. As long as the regenerator 40 is distant from the inlet valve 48, hot air is drawn in, cold air is blown out and the regenerators 36-39 are heated. - 45 - U11343

The flow résistance of the regenerator is active inthis case.

When the regenerator 40 moves towards the inlet valves,the valves remain closed. 5 The transition into the periodic operating Staterepresented above and in Figure 9 then occurs with therise in the mean température in the working volume.

In order to make the arrangement described operate as agas compressor, it is sufficient to drive the10 regenerators with an electric motor to execute theperiodic movements corresponding to Figure 9.

Cooling of the gas over a larger température différenceTx - T2 15 If larger température différences in the gas accepted by and. output from the working volume are tobe reached in the System represented in Figure 8, thisis achieved by virtue of the fact that in the timeperiod g-h-a a gas quantity of mass πίπ flows through 20 one of the valves 49, which is used like the valve 35in Figure 1 between the regenerators 39 and 40 from thepart of the pipeline.System 15.

With Ti, T2, Po unchanged, Pi can be selectedsuch that the gas quantity drawn in overâll' remains25 constant, that is to say this measure reduces by πίκ themass ioa of the gas which is drawn in in a hot state andforced out at a lower température and higher pressure.Less thermal energy is therefore exchanged during aperiod with the regenerators 36 to 39. 30 The pressure ratio Pi/Po must be lower in the operatingstate of equilibrium.

With Ti, Pi, Po unchanged, the same quantity ofthermal energy is fed during a period to theregenerators 36 to 39 only whenever the exchanged gas35 quantity is more intensely cooled. A larger température différence Tx - T2 can thus beachieved given the same pressure ratio Pi/Po- - 46 - 011 343

Given a constant pressure ratio Pi/P0, the températureT2 can be stabilized relatively simply by a simplethermostat control for the valve 49 corresponding tothe inlet valve 35 in Figure 1. 5 The inlet valve 35 is opened in this case only wheneverthe gas (just) exceeds the stipulated température at15.

If appropriate, it is also sufficient to reduce theflow résistance in the région of the inlet valve in 10 conjunction with rising température of the gas at 15,for example by a'baffle, controlled by a bimetal, whichchanges the cross section for the flow.

Cooling of the gas over a smaller température 15 différence Τχ - T2

If the aim in the System represented in Figure8 is to achieve a higher pressure ratio Ρχ/Ρο during thecooling of the exchanged gas by a spécifie températuredifférence, the gas quantity of mass ma is sucked from 20 the partial volume between the regenerators 39 and 40through the (driven) valve 49, which corresponds to theoutlet valve 35 in Figure 1, in the time period g-h-awith the aid of a ventilator which, in the idéal case,uses adjustable éléments to apply the pressure 25 différence to Po, which is small relative to Ρχ - Pozrequired for this purpose only in this time period, andthis gas quantity is fed to the space 15 of thepipeline System.

Four working volumes operate with a phase shift of 90°, 30 that is to say a spécifie ventilator can run uniformly,and only the outlet valves 35 must be controlled withsome expenditure of force and energy.

Consequently, with Τχ, T2, Po unchanged, the exchangedand cooled gas quantity m* is enlarged by ma, and a 35 larger quantity of thermal energy is fed to the regenerators 36 to 39 during this time period.

This more substantiel thermal energy is partially extracted again from the regenerators 36 to 39 in the - 47 - 011343 time period e-f-g during the effectively isothermalexpansion of the gas from Pi to Po, it being possible toachieve a higher pressure ratio Pi/P0, resulting in moreenergy being converted overall per period, in which5 case the thermal energy exchanged overall at theregenerators 36 to 41, and also the thermal lossesassociated therewith are increased in a far lowerratio. A better efficiency is thereby achieved overall. 10 If the mass flow through the adjustable ventilator canbe set in 3 stages (out, average, large), and the stageof large can always be switched on by a thermostatwhenever a spécifie température is undershot, thetempérature T2 can thereby be stabilized sufficiently 15 at a value with a relative low outlay.

Note: A ventilator for drawing in hot air is notnecessarily mandatory in order to operate the described20 arrangement as a gas compressor, since hot air isperiodically drawn into the working volume as soon asthe regenerators are moving. As long as the regenerator39 is distant from the inlet valve 48, hot air is drawnin, cold air is blown out and the regenerators 36 to 3925 are heated.

The flow résistance of the regenerator is active inthis case.

When the regenerator 39 moves towards the inlet valves,the valves remain closed. 30 The transition into the periodic operating Staterepresented above and in Figure 9 then occurs with therise in the mean température in the working volume.

In order to make the arrangement described operate as agas compressor, it is sufficient to drive the 35 regenerators 36 to 39 with an electric motor to exeçutethe periodic movements corresponding to Figura 4,Figure 5, Figure 6. - 4a - 01 1 343

Application as a refrigerating machine

The above-described System acting as a prime mover and having the working volume represented inFigure 8 can also, after a few changes, be operated as 5 a refrigerating machine which cools a gas quantity overa large température interval.

For this purpose, the ventilator (turbine) 14 thendriven must force the gas from the part of the pipelineSystem 15 at the pressure Po into the part 13 at Pi. The 10 sequence of movements represented qualitatively inFigure 9 I or Figure 10 I is run through in the reversetemporal sequence. The outlet valve 49 becomes an inletvalve by virtue of the fact that it is held openagainst the flow pressure in the time period a-h-g, by 15 the control System, in conjunction with an unchangedstop direction.

In this time period a-h-g, the partial volumes betweenthese regenerators are enlarged, and the meantempérature of the gas in the working volume is thereby 20 lowered starting from the maximum value.

The gas then flowing in at the pressure Px outputs

Zz thermal energy to the regenerators 36 to 39 uponcooling.

During the following time period g-f-e, thermal 25 energy is extracted from these regenerators by theexpansion of the gas between in each case tworegenerators (cf. above: prime movers).

The lowering of the pressure in the working volume isperformed with closed valves on the basis of the 30 lowering of the mean température of the gas to theminimum value by a displacement in conjunction withconstant relative spacings of the regenerators 36 to 41.

As shown above in the case of the description of the 35 prime mover, with the refrigerating machine, as well, the co-operation of the partial processes in the time periods a-h-g and g-f-e forms in the regenerators 36 to 39 a stepped température field T(r) which is linear in - 49 - 011343 the stroke direction and whose mean température Tn isbelow the coder température in the case of therefrigerating machine.

The temporal development of Tm(t) corresponds to the5 qualitative représentation in Figure 9 II in the caseof reversai of the temporal sequence and substitutionof max. TB(t) by min. Tm(t) . The mean température of thegas in the working volume is increased in the timeperiod e-d-c following thereupon upon telescoping of 10 the regerierators 36 to 39.

The inlet valve 48 of the prime mover in Figure 8 actsas outlet valve in the case of the refrigeratingmachine when it is held opeh against the flow pressurein this time period e-d-c, by the control System, is in 15 conjunction with an unchanged stop direction, and interalia because of the increase in the mean température inthe constant working volume, gas flows out · at aconstant pressure Po into the part of the pipelineSystem 15. 20 Before this gas is compressed anew by the ventilator(turbine), it absorbs in the heat exchanger 18 thethermal energy originating from the cooling of theother gas flow.

When the gas to be cooled is 'intro"duced directly into 25 the pipeline System of the refrigerating · machine at 15(cf. Figure 1) and extracted again at 15, the lossesand the design outlay of the heat exchanger 18 can beeliminated.

In ' the subséquent time period c-b-a, the mean 30 température of the gas in the working volume isincreased to the maximum value by the displacement ofthe regenerators 36 to 39 which because of the closedvalves leads to a pressure increase and the closure ofthe cycle. 35 Thermal energy is (additionally) extracted from. the partial volume of the working volume, which is diyided only by the regenerator 36, by virtue of the fact that the valve 48 or a valve, acting in parallel therewith, - 50 - with a smaller cross-sectional area is already openedbefore the pressure différence is completelycompensated.

Similarly, thermal energy is fed to the partial5 volume of the working volume, which is delimited onlyby the regenerator 41, by virtue of the fact that avalve acting in parallel with one of the valves 49 isalready opened before the pressure différence is completely compensated. 10

Cooling of the gas over a larger température différenceTx - T2

As in the case of use as a prime mover, in thecase of the apparatus represented in Figure 1 it is 15 possible for a larger température différence of the gasquantity of mass mA accepted and output by the workingvolume to be achieved when in the time period e-d-c agas quantity of mass mH flows out into the space 15through the valve 49, which acts in this case as an 20 outlet valve like the valve 35 in Figure 1 inconjunction with a stop changed relative to Figure 8,and which is held open in this time period e-d-cagainst the flow pressure by the control system.

With Τι, Ρχ, Po unchanged, the same quantity of thermal 25 energy is fed during a period to the regenerators 36 to39 only whenever the gas is more intensely cooled. A larger température différence Ti - T2 can thus be achieved given the same pressure ratio Pi/Po-

Given a constant pressure ratio Pi/Po, the température 30 T2 can be stabilized by a simple thermostat control.

The outlet valve 49 corresponding to the valve 35 inFigure 1 is opened in this case only when the gas(just) exceeds the stipulated température at 15. 35 Cooling of the gas by a smaller température différenceTi - T2

The System represented in Figure 1 anddescribed with the action of a gas compressor can, as 011343 - 51 - already represented above with reference to Figure 1,also be operated as a refrigerating machine when theworking volume and parts of the control System areexchanged for the arrangement represented in Figure 8.5 If, as in the case of the prime mover, the aim is alsoto operate with a spécifie pressure différence Pi - p0in the case of the refrigerating machine for a lessercooling, this can be achieved when the gas quantity ofmass me in the time period e-d-c is blown in from the10 space 15 through a further (driven) valve 49,corresponding to the inlet valve. 35, between theregenerators 39 and 40 with the aid of a ventilator.

As a resuit, in the operatihg State the regenerators 36to 39 are fed a larger quantity of thermal energy by15 comparison with operation without the valve 49,corresponding to the valve 35 and correspondingly morethermal energy is extracted again in thê case of theisothermal expansion in the time period e-f-g by anexpansion with a higher pressure ratio Pi/P0. 20 The advantages of these measures, or the control of thetempérature T2 are largely the same as in the case ofthe prime mover relating to Figure 1.

Heat pump —. 25 The Systems described above with the action of . refrigerating machines and in which the working volumerepresented in Figure 8 is integrated act as a heatpump when the control System drives the regenerators 36to 41 with an unchanged periodic sequence of movements, 30 and the working direction of the turbine 14 ismaintained, but the pressure increase is exchanged, onthe basis of an opening of a valve through which thegas flows in, with the pressure drop on the basis of anopening of a valve through which the gas flows out. 35 As a resuit, only the partial volume, delimited by the regenerator 36, of the working volume is heated,. and the partial volume delimited only by the regenerator 41, of the working volume is cooled. - 52 - 011343

Compared with the refrigerating machine describedabove, the temporal sequence of the mean températureT„(t) and the pressure P(t) against the stroke H(t) isdisplaced by half a period. 5

The cycle in the case of use as a heat pump

In the time period g-f-e, the pressure of the gas in the working volume is increased to the maximumvalue because of the rise in the mean température of 10 the gas owing to the displacement of the regenerators36-41 in the case of closed valves.

Because of the adiabatic compression of the gas flowingthrough the partial volumes between in each case two ofthe regenerators 36 to 39, these regenerators are fed 15 thermal energy.

Upon telescoping of the regenerators 36 to 39 in thetime period e-d-c, gas at the température TH isadmitted by the turbine from the working volume at thepressure Pi through the valve 49, which is being held 20 open, since the mean température is lowered.

In the time period c-b-a, the pressure of the gas inthe working volume is lowered from Px to Po because ofthe lowering of the mean température of the gas to theminimum value owing to the displacement of the 25 regenerators 36-41 in the case of closed valves.

The gas in the partial volume which adjoins the coderis expanded adiabatically and cools in the process. Inthe time period c-b-a, the mean température in theworking volume is increased with the displacement in 30 conjunction with a constant spacing between theregenerators 36 to 39, the cooled gas flows through theheat exchanger and extracts thermal energy at thetempérature Tk, and at Po the valve 48 outputs gas attempérature Tx in the time period a-h-g, since the mean 35 température T„,(t) of the gas in the working volume is increased.

If, simultaneously with this, gas with the température of approximately TH is pushed by the ventilator out of - 53 - 011343 the space 15 into the partial volume betweenregenerators 39 and 40 through the valve 49 acting likethe valve 35 in Figure 1, the différence in thetempératures TH - Tx is reduced in conjunction with the5 same pressure ratio Pi/P0.

As in the case of the prime mover, this measure ofmaking a change leads to a larger conversion ofmechanical energy in conjunction with thermal losses ofapproximately the same magnitude (cf. Figure 1). If gas10 passes from the working volume into the space 15 of thepipeline System through the valve 49, which correspondsto valve 35, controlled via the gas température at 15in the time period a-h-g, it is thereby possible toachieve a larger température différence of the15 exchanged gas (cf. refrigerating machine or prime movercorresponding to Figure 1).

Fresh air can be filtered and heated with this heatpump.

The regenerators in the working volume act as filters 20 and can be easily exchanged in the case ofcontamination. /

The thermal energy fed to the fresh air originatespartly from a colder heat réservoir such as the ambientair or the groundwater. 25 The thermal pump sketched can be designed such that theair virtually does not corne into contact withlubricants, and that the filters can be changed easilyupon contamination.

In order to be able to achieve a higher pressure ratio 30 P1/P2, the gas is extracted from the partial volume of the working volume between the regenerators 36 and 37.The design required for this purpose is comparable tothat for the exchange of gas into or from the partialvolume between the regenerators 39 and 40. 35 Use is made in a similar way for the purpose of guid.ing air, (cf. 50), of a tube 205 which is fastened on* the regenerator 36 and, while being slidingly sealed from the pressure housing, dips into a tube 206 (cf. 51) - 54 - 011343 connected thereto, from which the air is exchangedthrough valves.

Water in the pressure vessel 5 By comparison with the représentation in Figure 8, the outlay on a pressure vessel with the many sealscan be substantially reduced to a parallelepiped orcylinder with few openings when, instead of beingguided into a separate space 61 of the pressure vessel, 10 the tube bundle 42 is guided in the other directioninto a space which . is bounded only by the heatexchanger structure of the cooler 43.

For this purpose, the diameters of the tubes must beassigned to the regenerators in the reverse sequence. 15 These tubes are connected movably to one another by alever structure such as 57, 58.

The regenerator 41 is eliminated, and the valve 48remains unchanged.

The air guidance tube 50 likewise points in the other 20 direction and slips in a slidingly sealed fashion intos a tube which corresponds to 51 and is connected in a sealed fashion to the pressure vessel, it beingpossible to fit the outlet valve corresponding to 49 on the pressure vessel. 25 Fastened in each case on each of four tubes, which arefastened in each case on one of two differentregenerators (ideally: which are temporarily as fardistant from one another as possible) are two tensionedbelts of which one is wound on during the rotation of a 30 shaft led o.ut in a sealed fashion from the pressurevessel, while the other is wound off.

The tubes of each regenerator are thus driven by twoshafts, and the regenerators are guided in parallel.

Two each of these shafts are coupled outside the 35 pressure vessel to sprockets and a chain guided thereover on which in each case the connecting rod -89 or 69 of the chain drive shown in Figure 20 acts. - 55 - 5 10 15 20 25 30 35 011343 régionby a are and heat

The pressure housing is filled with water to the extentthat the cooler structure 43 dips in largely completelyin its lowermost position.

As a resuit, the conduits 45 and 4 6 and theperforations 63 and 62 for the cooling liquidsuperfluous.

This water is exhausted from the uppercooled or heated in the closed circuit exchanger outside the pressure vessel. The tube 50 alsoserves as overflow for the water level in the pressurevessel. Overflowing water is separated by centrifugalforce from the gas in a pressure tank arranged in thepipeline System downstream of the valve 49, since thewater-gas mixture enters the pressure tank, which has avertical cylinder axis, tangentially at medium level,and is extracted again in the middle at the top througha tube which projects approximately 30 cm into thepressure tank.

The water is led back from this pressure tank into thepressure vessel around the working volume through atube which can be sealed by a valve . actuated with theaid of a float by the water level tank. in this pressure

The water level can be varied periodically (byactuating a compression device) in the pressure vessel,and an (additional) pressurée change can thereby beachiéved.

It is also possible thereby to achieve for the flowthrough the regenerators 36 to 40 that there isfastened in a sealing fashion on the edge of each ofthese regenerators a métal sheet which also always dipsinto the water in the periodic operating State.

In order to minimize the losses owing to the heattransfer surface, this métal sheet must be providedwith a water repellent surface of low thermalconductivity. - 56 - 011343

Functioning of a gas compressor according to theinvention :

Hot gas + cold gas yields warm gas at a higher pressureIn order to be able to admit two gas quantities 5 of masses mi, mk at the températures Tx and Tk/respectively, into a working volume/ and to output themagain at a higher pressure at températures T3/ T4 lyingbetween Ti and Tk, it is necessary to make the followingmodifications by comparison with the working volume 10 represented in Figure 8Z as shown in Figure 24:

The regenerator 41 is eliminated, and the heatexchanger 43 is replaced by thé regenerator 207.

The regenerators 39 and 207 are thereforeinterconnected at a fixed spacing, and the regenerator 15 40 temporarily bears against them in each case.

Similarly, the regenerator 208, bearing temporarilyagainst the regenerator 207, is permanently connectedto the regenerator 38 temporarily bearing against theregenerator 39, the regenerator 209 temporarily bearing 20 against the regenerator 208 is permanently connected tothe regenerator 37 temporarily bearing against the // regenerator 38, and the regenerator 210 bearingtemporarily against the regenerator 209 is permanentlyconnected to the regenerator 36 temporarily bearing 25 . against the regenerator 37.

The exchange of air through the air guidance tubes 205and 211 is likewise performed predominantlysimultaneously like the exchange of air through the airguidance tubes 50 and 212. One of the valves 49 or one 30 of the valves 213 through which the air flows out of orinto the air guidance tube 212 is used like the valve35 in Figure 1 in the case of a changed stop direction.

The sequence of movements and the change in themean température Tm(t), or the pressure in the working 35 volume P(t) largely correspond nevertheless to the qualitative représentations in Figure 9. In the time period g-h-a, gas at the température Ti, or Tk is drawn in through valves. As shown above, a linear, stepped • 57 - 011343 température profile is yielded in the stroke directionin the regenerators between the valves. The gasquantifies flowing into the working volume must beappropriately controlled by valves in order to maintain5 a spécifie température différence in the cooling orheating of the periodically exchanged gas quantifies.If the cooler gas is to expérience only a slighttempérature change, as described above in the processof flowing in through a valve 49 acting like the valve10 35 gas is sucked out of the working volume with the aid of a ventilator.

Since the gas from two different partial volumes whichare separated from one another by a regeneratOr 40 canflow out from the working volume through different15 valves 49 and 213 into different spaces of the pipelineSystem, the température différences occurring in theevent of the température change can (together with avalve which acts like the valve 35) be varied over wideranges. 20 This type ôf entropy transformer is simpler toconstruct overall, since no heat exchanger (for exampleautomatic cooler) is required.

Moreover, steam cannot suddenly develop from escapedcooling water. 25 As already shown above, a System acting as a gascompressor can also act with slight changes as a heatpump or refrigerating machine.

This design can also be operated such that lukewàrm gasat a high pressure is forced periodically into the30 working volume by a turbine, and that hot and cold gasat a lower pressure flow out from the working volumeperiodically. In this case, it is essentially possibleto make use both of the cycle represented above inrelation to the heat pump, and of that relating to the35 refrigerating machine.

The respective température différences can additionallybe set with the aid of a valve which acts like thevalve 35. . 58 - 011343

Combination of refrigerating machine and prime mover

If hot gas and cooling water at the température

Tic are available, gas can be cooled by an entropy5 transformer with 2 working volumes below the cooling water température Tk.

In principle, for this purpose in the case of therefrigerating machine described above the drivenventilator 14 is replaced by a prime mover described 10 above, the hot gas being accepted by the workingvolume, which can be assigned to the prime mover, andbeing output in the case of higher pressure through theoutlet valve 49 or 4 into a space of the outline Systemto which a buffering pressure vessel can be connected, 15 and from which the gas, possibly after prior cooling toapproximately Tic, flows through the valve 49 acting asinlet valve, into the working volume which can beassigned to the refrigerating machine.

The gas, cooled to below Tic, flows out from this 20 working volume to the valve 48, and possibly the valve49 acting like the valve 35.

As represented above, the periodic flow through thesevalves of the two working volumes can be setappropriately to tune pressure and température 25 différences.

If the movements represented in Figure 4, Figure 5,

Figure 6 I proceed simultaneously in a working volume, the buffering pressure vessel can be of smaller dimension, or be eliminated. 30 This combination can also be used as a heat pump for heating a liquid. Further interesting combinations serve to increase the calorific value to a value of above 1.

Thus, one hot and cold gas quantity each are admitted35 from a first working volume, as described above, andoutput again at higher pressure as a cool gas quantityand accepted by a second working volume, which outputsit again as a warm gas quantity at the output pressure. - 59 - 011343

In this process, the liquid of a heat exchanger wascooled in the second working volume, or an additionalgas quantity was cooled.

If an isothermal heat source and an isothermal5 heat sink are available, it is of interest for thepurpose of heating or cooling gas for the compressor tobe replaced in the case of the Systems described above(acting as a refrigerating machine or heat pump) by aknown thermal compressor with isothermal absorption10 and output of thermal energy.

Additional change in the working volume

Because of the flow through the regenerators inconjunction with the drop in pressure in the working15 volume, the gas expands virtually isothermally.

In this process, the gas température changes onlyrelatively slightly, since the gas volume flowingthrough in a period is decisively larger compared withthe size of the partial volume of the working volume20 between two regenerators.

As a resuit, the irréversible phenomena in the case ofcontact between gas and heat exchange surfaces of theregenerators are less pronounced.

These advantages can be employed particularly25 effectively when, in the case of the machine relatingto Figure 8, the working volume is reduced by a pistonmoved periodically by the control System in the time.period in which the pressure in the working volumewould also rise in conjunction with an unchanged 30 working volume.

It is particularly important in this apparatus that, asshown above, above the regenerator 36 and below 41 gridplanes 108 and 109, respectively, prevent eddies andare moved by the control System such that they are35 largely flowed through only by the gas of constanttempérature.

Owing to the effect described above that a valve actslike the valve 35 in Figure 1, it is possible in the - 60 - 011343 case of this design as well to set the températureinterval in which the gas to be exchanged is cooled orheated.

If the gas volume is changed without the regenerators5 being flowed through in the meantime, the gas betweentwo regenerators is adiabatically expanded orcompressed in the process from Px to Po and therebycooled or heated, respectively. The periodic sequenceof movements is similar in this case to Figure 4, 10 Figure 5, Figure 6. The irreversibility in the case ofa subséquent flow through one of the adjoiningregenerators affects the efficiency more strongly thelarger the température change which occurred in theprocess was. 15 Since this effect also occurs in the case of the knownStirling engines, interest also attaches to astructurally simple design which corresponds largely toFigure 1 except for the regenerator system 11, with thechange that the regenerator System 11 is replaced by 20 the regenerators 37-40 with the associated controlSystem 42-55 from Figure 8.

The periodic sequence of movements can be gathered fromFigure 4, Figure 5, Figure 6 I. 25 Displacer with ambient flow

In the machine represented in Figure 21 the working volume largely enclosed by a cylinder aspressure housing 110, the valves 111, 112 and theslidingly sealed piston 113 is divided by cylindrical 30 displacers 114 into partial volumes:

These displacers 114 can be flowed around by theworking fluid, the gap between displacer and cylinderwall acting as a regenerator, and hâve in the directionof the cylinder axis an extent which is 3-10 times as 35 large as their maximum length of movement with respect to the pressure housing. - 44 - 011343

In the case of use as a prime mover, cooling isperformed by cooling conduits 115 outside the pressurehousing. A single displacer 14 acts as one of the corresponding5 regenerators 36-40 in Figure 8.

The arguments relating to Figure 9 can be taken overdirectly in the case of a transférable cycle ofmovements for a constant working volume (that is to saystationary piston in Figure 21) . 10 The valves 111 and 112 correspond in this case to thevalves 49 and 48, respectively.

The displacers 114 are driven, as in the case of theregenerators in Figure 8, by a bundle of concentrictubes 109, the tube with the largest diameter being15 slidingly sealed with respect to the piston 113, andeach other tube being slidingly sealed relative to thetwo tubes with the next smaller, or néxt largerdiameter.

Outside the working volume, driving can then be 20 performed in conjunction with only a relatively slightchange in the working volume (up to 10%) by the piston113 with the aid of a lever structure 117, as inFigure 8. The corresponding connecting rods of theChain drive described in relation to Figure 8 can act 25 directly on the corresponding tubes of the tube bundle109.

This design is ail the more interesting the lower theratio of working volume to cylinder surface is, sincethe heat exçhange with the cylinder surface is designed30 to act in this case like a regenerator.

In order to intensify this action, this active surfacemust be enlarged by fine slots (in the strokedirection) in the case of working fluids of low thermalconductivity. 35 If an even larger heat transfer surface is required to achieve a high level of efficiency, a regenerator-to be flowed through must be arranged in the interior of the displacer, and the flow résistance in the gap between - 62 - 011343 the cylinder wall and displacer must be of the sameorder of magnitude as in the case of the regenerator,in conjunction with a comparable rate of flow. Anadditional seal can be required for this purpose. 5 The heat transfer surface for cooling through thecylinder wall 115 is enlarged in this case by slots inthe stroke direction, and the working fluid flowsaround the displacer in this région and must also flowthrough a regenerator in this displacer. 10 This machine can also be designed for operation with a liquid as working fluid in the working volume.

The technical problème arising in this case(pressure résistance, température, stability, seals)were solved by Malone in 1931 for water as working 15 fluid in machines which resemble a Stirling engine indesign.

Sources: Malone: A new prime mover - J. of the RoyalSociety of Arts, Vol. 97, 1931, No. 4099, p. 680-708or: Die Entwicklung des Heifiluftmotor [The development 20 of the hot air engine] by Ivo Kolin, Professor ofThermodynamics, translated into German by Dr C.Forster, pages 54, 55 c E. Schmitt, D-6370 Oberursel, PO Box 2006, Tel:(06171) 33Ç4, Fax: (06171) 59518. 25 As shown in Figure 1, this working volume can becoupled to surrounding Systems, when these are designedfor the appropriate pressures and pressure différencesfor liquids, for example: instead of a gas ventilatoror gas turbine, a high-pressure pump. As already shown 30 by Malone, compact machines with a high mechanicaloutput can be built by using a liquid as working fluid.

Sealed displacer

Thermodynamically, the working volumes of the 35 entropy transformers in Figure 22 can be describedusing the same models as can be linked to Figure _4,Figure 5, Figure 6 or Figure 9. 011343 • 63 -

The design represented in Figure 22 looks verydifferent, in contrast.

The working volume is largely delimited by a pressurehousing 128 and inlet and outlet valves 130 and 129a,b.5 Partial volumes are delimited in this working volume bythe regenerators 131-136, which are stationary relativeto the pressure housing, the partitions 137-141, whichare connected to the regenerators 131-135, walls of thepressure hoùsing, and displacers 142-146, which are10 slidingly sealed on these walls.

In the operating State, the periodic change in size ofthese partial volumes corresponds to the periodicallychanged strôke différence of the correspondingregenerators in Figure 91. 15 In order to achieve this periodic cycle of movements,the displacers 142-145 can be moved periodically in asimultaneous fashion.

The gear racks 146-149 fastened on these displacers aredriven by gear wheels on a shaft 150a. 20 This shaft is led in a sealed fashion through thepressure housing out of the working volume and wound onz to or off it are the ends of a chain 150 which is tensioned over two sprockets 151, and which is actedupon by the connecting rod 152 of a chain drive design25 such as that driving. the regenerator 36 in Figure 8.The shaft 154 driven by an electric motor connecte thischain drive to a further similar chain drive 155, whichmoves the displacer 14 6 in the same way, such thatthere is a phase shift of approximately a quarter.30 period relative to the movemènt of the . otherdisplacers.

By contrast with the displacers in Figure 21,each of the displacers 142-145 in Figure 22 is adjoinedby one of the partial volumes between two of the35 regenerators 131-135, and by the partial volumeadjoining the cooler 156. . (6 . 011343

The displacers 142-145 are no longer permitted to beflowed around in practice, since the targetedequilibrium is not created otherwise.

So that the regenerators 131-135 can be flowed around5 as uniformly as possible in the time period a-b-c,d-e-f, g-h-j (cf. Figure 9), in the région which isinserted between two regenerators the displacers hâves lots running from one regenerator to the other and in the stroke direction. 10 The dead volume thereby produced can hâve a veryunfavourable effect in some applications. A further valve 129a can be used like the valve 35 inFigure 1.

As represented in Figure 8, it is also possible 15 to construct or use the design of Figure 22 as a primemover, refrigerating machine, heat pump, ....

Liquid displacer piston

The design represented in Figure 22 and as 20 represented in Figure 23 is modified for a differentdesign.

In this case, the displacer pistons are designed as anoscillating liquid column with a float in a U-shapedcontainer. 25 The movement of the liquid displacer piston iscontrolled and driven by a belt 159 which is wound ontoa shaft 158 in a tension fashion and fastened on thefloat 157.

Since the liquid displacer pistons largely execute the 30 same periodic movements as explained in relation toFigure 22 with Figure 9, it is possible in theoperating state in the case of this design, as well,for a plurality of liquid displacer pistonscorresponding to the displacer pistons 142-145 to be 35 driven from a shaft 158 corresponding to 150a.

The periodic movement of this shaft 158 can be controlled and/or driven as described in relation to

Figure 22. - 65 - 011343

Before liquid can pass into a hot space past a float157, which could lead to a dangerous explosivedevelopment of steam, the valve 160 is to be closed bythe extreme position of the float 157 and the flow5 rate.

In order to achieve a periodic movement more similar toFigure 3, this valve 160 remains closed by beingtemporarily locked during the time periods a-b-c withan extreme position of the corresponding float. For the10 same purpose, the displacer 157 is also temporarily. locked when it is pressed against the seal 161permanently connected to the pressure housing.

The surfaces of the heat exchanger 162 are heated orcooled by being dipped into the oscillating liquid.15 Overall, thermal energy is exchanged by the pressurevessel and the surroundings partly by the continuousexchange of the liquid oscillating in the pressurevessel.

During the time period with an above average pressure20 in the working volume, a portion of this liquid willflow through the valve 163 and the heat exchanger withthe surroundings 164 into the standby space 165 inwhich, because of the enclosed gas volume, a pressurechange can take place only by a change in the’ liquid 25 quantity contained.

This quantity of the liquid flow during the time periodwith a below average pressure flows back again throughthe valve 166 to the periodically oscillating liquid.

The valve 166 acts like a nozzle in relation to use as30 a prime mover.

The oscillating movement of the liquid column is driventhereby.

In order to amplify the compression, in the operatingState the working volume for the working fluid, which35 traverses the cycle, is reduced in common with thetotal volume of the working volume and the volume ofthe oscillating liquid by displacing the slidinglysealed piston 167 in the time period a-b-c, and - 66 - 011343 enlarged again in the time period e-f-g. The mechanicalenergy thereby exchanged can be temporarily stored atleast partially in the oscillating liquid coluxnn whichadjoins the piston 167. 5

Minimum of two heat exchangers in a pressure housingaccording to the invention

If a liquid is to expérience a températurechange over a large interval through contact with a 10 cycle, each of the regenerators 131-134 in Figure 22must be provided with a heat exchanger on the same sidewith reference to the through flow as in the case ofthe régénérator 135.

The liquid can then flow through these heat exchangers 15 in sequence and exchange thermal energy at a pluralityof température levels in the process (cf. Figure 3).The quantity of the working fluid in the partialvolumes of the working volume which are divided withoutoverlap by the regenerators with heat exchangers are 20 then largely at the température of the heat exchangerin each case. /

If the working means flows in the operating State intoa working volume of a prime mover in accordance withFigure 8, it mixes with coder working fluid. The 25 thermal energy thereby output is equal to theirréversible phenomena owing to thermal conduction,shuttle losses or limited quality of the regenerators.The resuit of this overall is a smaller periodic changein the mean température of the working fluid and thus, 30 in particular in the case of a smaller températuredifférence from 200°C, a substantial decrease in theconverted mechanical energy.

Since the irréversible phenomena (cf. above) arereduced to a much lesser extent with this température 35 decrease, the resuit is a substantial réduction in efficiency.

Likewise associated with a lesser design outlay is a design based on Figure 23 or Figure 21, since here, as - 67 - 011343 well, the beat exchangers need not be moved, and theconnections for the liquid exchange of the heatexchanger présent no problem.

If a change in température of the gas which5 corresponds approximately to the change in températureof the liquid through the heat exchangers is achievedby the adiabatic expansion in the external turbine, thearrangement of the inlet and outlet valves is performed as in Figure 22. 10 In the case of the prime mover, the gas exits from thepartial volume of the working volume at its highesttempérature and enters the partial volume adjoining theheat exchanger at the appropriate température.

If the change in température of the gas is 15 substantially smaller in the case of the adiabatic expansion in the external turbine than the change in température of the liquid, the gas is accepted throughvalves into a (the hottest) partial volume of theworking volume and output again therefrom. 20 What is important in general is that gas quantifies aremixed or contact takès place with heat transfersurfaces in conjunction with the smallest possibletempérature différences. 25 Intégration of engine + thermal gas compressor

The thermal energy output by the exhaust gas of a spark-ignition or diesel engine upon cooling can beused to generate additional mechanical or electricalenergy or to supercharge the engine with filtered fresh 30 air at a higher pressure, and thereby not to hâve toexpend mechanical energy for a turbocharger orcompressor, thereby achieving a better performancevolume and in any case a higher level of efficiency inrelation to an engine without this supercharging. 35 By comparison with an engine without supercharging, amore favourable engine performance volume is possiblein conjunction with an improved level of efficiency,since the compression of the air is performed at an - 68 - 011343 unfavourable level of efficiency when an engine issupercharged by a compressor or turbocharger.

Further synergy effects are achieved by virtue of thefact that no turbine and no additional generator are 5 required to convert the energy of the compressed airinto electrical energy.

Intégration of gas turbine and thermal gas compressor

In a fashion largely similar to above in the 10 case of the internai combustion engine, the thermalenergy output by the exhaust gas of a gas turbineduring cooling can be used to feed filtered, cool freshair at high pressure to the gas turbine.

The compressor of the gas turbine used in this process 15 can be designed such that it requires less drive energyin conjunction with an unchanged pressure in thecombustion chamber and with an unchanged gas flow rate,and this leads directly to a higher load power inconjunction with the same fuel consumption, and to a 20 higher level of efficiency.

Because of a synergy effect, in this case the level ofefficiency is higher than the sum of the level ofefficiency of the original gas turbine and the level ofefficiency of the thermal compressor (gas compressor), 25 since the power produced by the thermal compressor forthe partial gas compression can be achieved by theoriginal compressor of the gas turbine only with a lessfavourable level of efficiency, driven by the tappingof mechanical shaft output. 30 The use of a conventional gas turbine is also possible,if appropriate. It is then possible to expect arelative pressure rise in the gas turbine whichdecreases continuously from the fresh air inlet up tothe exhaust gas outlet, as a resuit of which there is 35 an increase in the power density and the level ofefficiency.

Spécial solar absorber for heating working means

Design principle:

Combination of: optical concentration by means of a parabolic fluted5 mirror, translucent insulation and flow through the translation insulation.

It is thereby possible for high températures to beachieved with a low outlay, and for the advantages ofthe principle of the invention to be fully utilized for10 the use of the solar energy.

In this case, glass rods 251 are arranged in a fashionlargely parallel to a plane which divides the reflectedinsolation of a parabolic fluted mirror into two beamsof equal intensity, and in a fashion virtually adjacent15 to a plane, perpendicular thereto, through the focalline 250 of the parabolic fluted mirror such that onlÿ• a small fraction of the radiant power reflected in thedirection of the focal line arrives, in conjunctionwith an idéal alignment of the parabolic fluted mirror,20 in the région of the end face near the focal line ofthese éléments.

The surfaces of the glass rods 251 which run parallelto the perpendicular to the focal line finally reflectthe irradiated sunlight in a directed fashion, and the25 thermal radiation of a blackbody at a température of700°K is absorbed as far as possible.

These glass rods are arranged in a plurality of rowswith only small slots and, together with a glossy métalsheet which has surfaces parallel thereto, surround a30 flow channel 252 parallel to the focal line 250 whichis supplied with air from a flow channel 253 parallelto the focal line 250 and with a larger cross sectionthrough at least one connecting channel 254, and fromwhich the air flows through the slots between the glass35 rods 251.

This air is directed away from the focal line by- theconcentrated insolation onto an absorber structure 255 - 70 - 011343 on which the air is heated by the solar energy whileflowing through.

Adjoining the absorber structure is the hottest flowchannel 256, which guides the hot air to a collector 5 channel.

The solar radiation is absorbed on surfaces which alsoreflect in a directed fashion, absorb blackbodyradiation at the température 700°K and are arrangedsuch that the absorbed energy per surface is as 10 constant as possible so that the heat transfer fromthis surface to the working means proceeds (despite thelow thermal conductivity or thermal capacity of saidmeans) takes place with minimal exergy losses (forexample a glazed slotted métal sheet). 15 The surface of the absorber can be increased byincreasing the number of the surfaces, which are alwaysaligned to be ever more parallel with the increasingnumber, the air being required to flow through only onesurface from the focal line in order to pass into the 20 hottest flow channel 253.

Fitted upstream of the focal line in the direction ofirradiation is at least one glazed fiat slotted métalsheet 257 in whose plane the focal line also lies.

When a larger quantity of air flows overall through the 25 glass rods 251 per time interval in a spécifie sectionof the focal line than flpws through the absorberstructure 255, an air flow is formed in the région ofthe focal line against the direction of radiation andensures by the formation of a nonlinear température 30 profile that a spécifie quantity of air arrives in ahotter State at the absorber structure than without theformation of this température profile.

In order to be able to implement a satellitesolution of the power supply by means of solar energy, 35 for example for a remote hospital in a desert région, an entropy transformer is required in which the described collector with a parabolic fluted mirror heats air which heats a heat exchanger, likewise 011.3 4.3 described, and at least two parallel-connected workingvolumes which are coupled to this circuit in parallelwith the heat exchanger and in each case supply withcompressed air a turbine which drives a generator. 5 Cooling by water is performed via a large water tankwhich serves as an intermediate store, so as to be ableto cool the water to lower températures at night.Wherever thermal energy is required at températuresabove 80°C, as in the laundry industry, large-scale10 catering or in disinfecting, hot air is directly cooledfrom the store. As a resuit, these consumer? cause theappearance of a lower peak load in the network. A solar collector which heats a gas over alarger température interval is protected by the15 dépendent Claim 155 and the following daims.

An exemplary embodiment characterized in Figure26 has two layers of translucent insulation 265, 266 between a transparent cover 260 and an insulated rearwall 261, arranged in parallel, between three spaces,20 running parallel thereto, with flow channels 262, 263,264 for the gas.

The flow channels run at an angle of 45e to thecollector channels 267, 268, 269 running in parallel.Flow channels which are separated from one another (26225 and 263) (263 and 264) only by a layer of translucentinsulation cross one another.

The gas flowing from the translucent insulation isextracted from each flow channel 262, 264 which adjoinsthe translucent cover and the insulated rear wall, the30 extraction being performed by a collector channelthrough a valve 270 or 271 controlled as a function oftempérature, the differential température in relationto the outside air being décisive at the transparentcover 260, and the absolute température being décisive35 at the insulated rear wall 261.

Gas is blown into each flow channel 263 arrangedtherebetween by a ventilator 272 from the appropriatecollector channel 268. - 72 - 011343

These ventilators 272 are ail arranged on a shaft 273and dimensioned such that flowing into each flowchannel 263 is a gas mass flow which is largelyproportional in each case to the radiant power 5 irradiated onto the surface of the appropriate flowchannel.

The translucent insulations 265, 266 consist of optionally uncoated or coated métal foil which absorbsthe infrared radiation of a blackbody at a température 10 of 700 °K as far as possible and reflects the sunlightin as directional a fashion as possible, or of a thinmétal sheet with an appropriate surface and slots 274parallel to the transparent cover.

By means of an alternating arrangement of fiat and 15 corrugated layers (cf. corrugated cardboard), it beingpossible to lay through each point of the métal a linewhich runs as far as possible overall in the materialor is at least not far distant therefrom, and isparallel to a main direction, it is possible to achieve 20 a structure which passes the direct insolation withoutsignificant losses by absorption or scattering at least ,/ given a suitable alignment.

The smallest surface largely bordered by métal andperpendicular to the main direction in the translucent 25 insulation has a size in the région of .0.25 cm2 to2 cm2. A métal fabric 275 which is coated in anoptically selected fashion or blackened is optionallyarranged in the région of the insulated rear walladjacent to the translucent insulation, thus providing 30 an enlargement of the flow résistance. The aim of thisflow control is to achieve a flow rate through amaximum surface area in the translucent insulationswhich is as constant as possible.

The transparency of the gas is used in this case when 35 the translucent insulation is flowed through. Formed as a resuit of the coopération of through flow, thermal conduction and absorption of the radiant energy is a nonlinear température profile which runs flatter on the 011343 side of the insulation, which is flowed through, in therégion of a plane from which the flow enters theinsulation. A lower energy flux is therefore transferred through5 this plane by thermal conduction.

The overall arrangement must track the solar positionsuch that the direction of irradiation corresponds tothe main direction of the collector.

Overall, a final température which is very high for 10 fiat collectors can be achieved with this type ofcollector, partiçularly when several are connected insériés. A sériés connection with the collectors described above, which also exhibit optical concentration, is very effective, since each collector 15 is used in a fashion corresponding optimally to itspossibilities.

Pressure change and mechanical energy A cylinder which dips with a vertical axis and20 a downwardly directed opening into a container with liquid can, for example, be used for directly driving adepth pump for conveying water when gas flows into thecylinder, which is moved vertically periodically, atits deepest position and flows . out again through25 controlled valves at its highest position.

The valve control is as for a historical steam engine.The différence in the hydrostatic pressure correspondsapproximately to the change in pressure of the gas asit expands through this partial System. 30 The resuit without valves is a partial System whichfunctions and is designed like a historical water-wheelin conjunction with exchangé of liquid and gas, both atthe top and at the bottom.

In this case, an apparatus such as a historical water- 35 wheel is moved largely below the liquid surface of an overall container. 011343 - 74 -

Because of the low viscosity of the gas as comparedwith the liquid, it is necessary here to pay greaterattention to sealing.

This is solved without a problem by having the gas flow5 into and out of a container whose opening and axis ofsymmetry are oriented in a tangential direction and perpendicular to the shaft axis.

The container is moved by the rotation such that apartfrom the liquid surface of the overall container there 10 are only liquid surfaces adjoining the container wallduring the prédominant time periods.

Gas is fed into or extracted from a container in as lowas possible a position as far at the top as possiblefrom the side through the latéral cover, which is 15 fitted around the wheel perpendicular to the shaft axisand sealed in a fashion sliding thereagainst.

The other periodic exchange of gas occurs when thecontainer is flooded, or runs empty upon surfacingabove the liquid level. 20 This arrangement can also be used for compressing gaswhen the shaft is driven in the reverse direction to / / the case of use as a drive.

In order to achieve high powers above a few 100 kW under atmospheric pressure conditions, the 25 surface of the regenerators 274-277, through which flowoccurs, must be appropriately enlarged.

In order to achieve a compact housing shape 278, thestationary regenerators 274-277 are multiply folded ata largely constant spacing along parallel lines 278 and 30 surround on both sides at least one disc-shapeddisplacer element 279, moving parallel theretoperiodically, as far as into the région of the centralaxis of the displacer element, which is parallel to thefold edges. 35 The other half of the displacer element is correspondingly surrounded by the adjacent regenerator.

In the case of a round design, the fold edges of the regenerator lie correspondingly on concentric circles. 011343 • 7« .

At least one of the regenerators is optionallyconnected to a hydraulic or pneumatic piston, which canbe moved in the stroke direction, or a membrane bellowswhich is emptied or filled via control valves with5 liquid or gas from the space around the liquid surface,removed from the corresponding working space, of thecoupled oscillating liquid column.

In order also to be able to implement morespécifie movements such as are required, for example,10 for directly driving the bipartite displacer structuredescribed below with liquid in the working space andmoving regenerators, the movement is optionally tappedby a rod or a tensioned draw element (such as a cableor chain) via a movable connection by an endless draw15 element such as a closed chain or toothed belt which istensioned in a force-closed fashion over a plurality ofwheels, rotating at a relatively uniform angularvelocity, such that thè angle between the two élémentsduring time periods of the operating state in which the20 driven element is to be moved only slightly in theworking space (regenerator, displacer) is about 90° and' becomes smaller the quicker the movement of the drivenelement in the working space is to be performed. A pipeline System with undérpressure, such as25 the boiler over a heater, is coupled to the inlet valveof a heat engine according to the invention.

This System is used as a dust-extractor.

The outlay on the housing 280 around theworking space can be decisively reduced by using curved30 shapes.

The moving regenerators 281-284, designed in the formof a . latéral conical surface, hâve good dimensionalstability, can be produced with an acceptable outlay,and can be driven exclusively in the région of the cône35 vertices.

For sealing purposes, each regenerator is connected tothe latéral surface 285 of a sheet-metal cylinder or toa comparable latéral surface of a pointed conical - 76 - 611343 frustum which dips at the lower end continuously into aliquid 286 and thus prevents the regenerator from beingflowed around in the event of stroke movements parallelto the cylinder axis of the sheet-metal latéral 5 surface. Conical frustrons which narrow upwards arefavourable as a shape for the sealing éléments 285dipping into the liquid and for the latéral housing280, and présent no problem since an expansion of theupper région takes place owing to the température 10 increase.

The angle of the conical frustum must be relativelyacute so that the gap between two sealing éléments 285is not too greatly enlarged when they are moved apartfrom one another, since irréversible processes proceed 15 in this gap owing to the heat transfer.

The purpose of driving and guiding the regenerators andsealing cylinders is served by concentric tubes 286which are guided on a stàtionary tube 287 on the common axis of the cylinders, and are connected to the 20 regenerators 281-285 in the région of the cône Z Z vertices. The tubes 286 are provided in this région in the axial direction at least with a slot through which the inner tubes are connected ‘ to the corresponding regenerators 25 281-284. The tubes 287 projeçt upwards decisively over the uppermost regenerator 281 into a spécial indentation288 in the working space surrounded by the housing, andare guided there in a sliding fashion on a stationary 30 tube 287.

Below the liquid surface 288, the cylinders 285 arelikewise respectively connected to one of the tubes 286also guided slidingly in this région.

The space between the liquid surface 288 and the 35 lowermost regenerator 284 at its lowermost position in the operating state is largely filled by an at least bifurcate displacer structure 289 which is moved apart in the event of an upwards movement and clears flow 011343 - U - channels for the working gas on the parting surfacesrunning obliquely relative to the direction ofmovement.

This displacer structure 289 is likewise guided in the5 région of the cylinder axis and moved either via aseparate drive or by springs between the regenerator 284 and individual displacer éléments and a sprung stopfor the stop at the liquid boundary surface 288.

If this displacer 285 is optionally permanently10 connected as an alternative in unipartite form to thelowermost regenerator 284, two parts fewer need bemoved.

In return, there is an increase in the dead . spacebecause of the necessary permanently présent air15 channels through the displacer 289 or on its surface.

The heat exchanger 290 is optionally fastened directlybelow the lowermost regenerator 284 and flowed throughby a heat exchanger medium, or it is fastened with thelowermost regenerator 284 on the cylinder 285 and/or20 the corresponding tube 286, and dips into the liquid286 in the lowermost position, there being an exchange • / of the thermal energy which is compensated in the caseof continuous operation by a stationary heat exchangerwhich is connected, for example, to the hot water25 treatment System of the building.

Working gas is periodically exchanged through at.leastone valve 291 in the housing above the uppermostregenerator 281. This exchange is compensated by theexchange of working gas, which is performed in the30 stroke direction from the partial space above thelowermost regenerator 284 by at least one penetratingtube which is fastened directly thereon at one end andalways dips into the liquid 286.

Arranged concentrically in this tube in a fashion 35 sealingly connected to the housing is a tube 293 which projects above the liquid level 288 and from which the gas exchange is performed through at least one valve 294. - 78 - 011343

Liquid can flow into this tube in the event of a rapidmovement or a blockage of the lower regenerator.

If this has to be avoided because of a disturbing orcritical development of steam there is arranged therein 5 at least one further tube whose upper edge projectseven further beyond the liquid level.

The interspace is connected through a separate valve,which is controlled together with the gas valve, to aspace which is also connected to the space with which 10 the working space exchanges gas through the adjoiningtube.

Depending on the design of these valves, it canoptionally be simpler as an alternative to monitor thewater level via an additional corresponding tube 15 arrangement, cf. 295, in which the tube for the gasexchange is eliminated.

This tube, cf. 295, is also fed water via a furthertube, cf. 296, which is used as an overflow and isarranged in the stroke direction largely inside the 20 liquid with an opening at the level of the largelystationary liquid level, without penetrating a

. Z regenerator. A porous structure, cf. 297, is integrated into theJ.ower région of the overflow, cf. 296, - without the 25 possibility of being flowed around, in order that thelowermost regenerator cannot be flowed around by thistube arrangement.

Movably fastened on a plurality of regenerators281-284 or éléments rigidly connected thereto are 30 intermediate levers which in each case are connectedmovably at the other end to different points of atleast one further main lever which is movably connectedto the housing optionally directly or via a lever.

The uppermost regenerator 281 acts movably directly or 35 indirectly on the main lever at a point which is arranged closest to the point at which the direct- -or indirect movable connection to the housing is made. - 7v - 011343

The mirror symmetry of this lever arrangement relativeto a plane in which the stroke direction also lies hasthe effect that no latéral forces are transmitted ontothe regenerator structure, particularly when the lever5 arrangement is situated below the surface centroids.

One of the lowermost regenerators is movablyconnected via connecting rods 298 to two drivencrankshafts 299 which are arranged and moved in amirror-symmetric fashion relative to a plane in which10 the stationary guide element 287 lies in the strokedirection.

It follows that in relation to the stroke directionweaker latéral forces are transmitted to theregenerator arrangement 281-285 which would hâve to be15 absorbed by the guides 300 and lead to additional wear,particularly when the connecting rods 298 run below thesurface centroid of the regenerators 281-284.

Fitted on the crankshaft 299 opposite the connectingrod bearing are masses which at least partially20 compensate the weight of the regenerator arrangement bytheir weight force.

As an alternative for the drive System of theregenerators, a plurality of regenerators · areoptionally movably connected at least to one each of25 the connecting rods, which are mounted with the otherends on spindles of at least one crankshaft, ail ofwhich can be intersected by a line through the axis ofrotation, parallel thereto, of the crankshaft, thebearing for a connecting rod of the lowermost 30 regenerator being furthest distant from the axis ofrotation of the crankshaft, and the bearing of theuppermost regenerator being closest.

As in the case of a comparably used Stirling engine, atleast one regenerator is driven with a phase shift of a35 quarter (25%) of a period relative to the volumechange.

In the time period with the lowest pressure in theworking space (working space = working volume) with-a 011343 80 - periodically varying volume, in the case of operationas a prime mover the periodic acceptance, and in thecase of operation as a heat pump or refrigeratingmachine the periodic output of working fluid is 5 performed through a valve 291 which adjoins in theworking space a partial space 301 of constant volumewhich is completely surrounded by two regenerators 302-303, one of these regenerators 302 adjoining thehousing relatively directly. 10 As an alternative to the drive described above, atleast one guide element is optionally designed in thestroke direction 287 at least partially as a threadedrod or recirculating bail screw, and an elementengaging therein moves at least one regenerator, 15 connected thereto, by rotating the threaded rod orrecirculating bail screw in the stroke direction.

As a spécifie alternative, the threaded rod orrecirculating bail screw optionally has régions withdifferent screw pitches in which the connecting 20 éléments of the regenerators moved at different speedsengage, with the resuit that they are moved atz different speeds in the stroke direction during arotation of the threaded rod or recirculating bailscrew, it being possible thereby for the number of 25 moving parts to be substantially reduced. A heat engine according to the invention can thus bedesigned with only five moving parts and the necessaryvalves.

In these alternatives, a recirculating bail 30 screw and connecting éléments engaging there which eachhâve a closed, intercrossing threaded track areoptionally used to move the regenerators periodicallyup and down during rotation of the recirculating bailscrew at constant speed in the stroke direction, or at 35 least one threaded rod or recirculating bail screw is periodically rotated in a different direction, optionally by a mechanical control System or directly by an appropriately controlled motor. 011343

In this case, for a design which can be implementedusing commercial], y available parts, the lowermostregenerator engages in a recirculating bail screw witha closed track, and at least a portion of the other5 regenerators engage, rather, in conventional threadedtracks whose tracks are not closed.

The lowermost regenerator is thereby prevented fromstriking the liquid surface.

The guide tube is periodically or continuously flowed 10 through in the middle by working gas from the coolestpartial space. A radial ventilator is connected t'o the tube with theaid of a thread or recirculating bail screw-, and thetube in this région is opened laterally just as in the15 coolest partial space on the other side of the middleof the tube. A separâte pipeline for working gas leads from thespace adjoining one opening of the guide tube to thespace which adjoins the other opening in the région of20 the liquid surface.

It has already been shown that a periodic compressionincreases the energy conversion by periodicallychanging the volume of the working space.

This is achieved most effectively by virtue of the fact 25 that a tube 304 with a water column 305 oscillating inthe operating State is coupled to the coldest région inthe working space.

For this puxpose, a tube 306 is guided out of thehousing 280 in the stroke direction with an opening30 above the liquid level 288.

In the case of a System with a single working space,the other end of the coupled tube 304 of the liquidcolumn 305, which resonates periodically, is connectedto a pressure vessel 306. 35 The two spaces 308, 309 adjoining the ends of the liquid column 305 are optionally connected 307 at* the level of the targeted average liquid surface 310 to a pressure reducing valve 311, with the resuit that for - β2 · ' 0113 43 pressure compensation only a negligible quantity ofliquid, but a substantial quantity of gas, can flowthrough periodically, or a lower fraction of theworking gas is fed per period from the working space to 5 the pressure vessel through a tube System with a non-return valve and a further pipeline with a non-returnvalve is connected to the pressure vessel at thetargeted average level of the liquid surface, whichleads into the space which adjoins the other end of the 10 liquid column, as a resuit of which only a negligiblequantity of liquid, but a substantial gas flow, flowsperiodically.

The quantity of gas in the pressure vessel isstabilized thereby. 15 Fitted on the connection from the working space to thetube with the oscillating liquid column is a valve 312which has in the flow direction of the working space astop against which the valve plate 313 is sealinglypressed as soon as the liquid column has moved too far 20 in the direction of the working space.

When this valve is closed, the overpressure building up ,·/ · . upstream of it can reach the other end 309 of theoscillating liquid column 305 through a pressure reliefvalve, leading out of this space 308 and connected 25 correspondingly to the tube System of the oscillatingwater column, and a spécifie tube (into the pressurecontainer). A further pressure release valve 315, coupledto the same space 308, leads to an external container 30 316 instead of to the pressure vessel 309.

The liquid level in this container is kept constant atthe highest possible level.

It is connected with the aid of a further non-returnvalve to an end of the tube System around the 35 oscillating water column, through which a smallquantity of the liquid can flow back again in spécifietime periods. • 83 · 011343

Fastened on the lowermost periodically moving regenerator is a tube 295a which runs in the strokedirection and into and from which gas can flowunimpeded from the partial space adjoining thereabove,5 and whose lowermost end always dips into the liquid.Arranged concentrically in this tube 295a in a fashionsealingly connected to the housing is a tube 295b whoseupper edge corresponds to the level of the maximumliquid surface 288 présent at the sealing cylinder 28510 of the regenerator, and which leads, in a région in theworking space above the safety valve 313 at the accessto the oscillating water column 305, from which thepossibly overflowing liquid reaches the liquid of theoscillating liquid column 305. 15 A tube 299 whose upper edge ends in the lowermostpartial space at the level of the targeted liquidsurface 288 in the working space is connected as fardown as possible to the previously described tube 295which leads to the oscillating liquid column 305. 20 When the liquid level in the working space 288 ishigher than the connection of the tube end, connected ' thereto, at the oscillating liquid column in the caseof the valve 313, a porous structure 297 which cannotbe flowéd around is integrated into the abovedescribed 25 tube System upstream of the inlet.

Every time the machine is started, a spécifie quantity(for example 31) of liquid is fed to the working spacethrough a valve.

The remainder of the management of the various liquid 30. quantifies in the machine is performed automaticallyusing the design described above and the functionalrelationships.

The pressure vessel can optionally be replacedby a further working space in which the thermodynamic35. cycle proceeds offset by half a period in conjunctionwith an identical length of period. - 84 -

Cl 1343

The principles of optical concentration andtranslucent thermal insulation are combined in thedesign of the solar collector.

The mirrors therefore do not hâve to lead to high5 concentration factors (>100).

Because of the only one-dimensional curvature, it isfavourable to use mirror flûtes 317 to construct thecollector inexpensively.

In craft terms, a fluted mirror 317 is implemented with10 a high degree of flexibility as regards dimensions andshape, without an expensive production structure fromcommercially available materials such as, for example, from wood and sheet métal.

For this purpose, the profile 319 of the flûte is eut15 out from a plate material 318 such as plywood, with the aid of a compass saw.

At least two of these plates are connected in a largelyparallel fashion such that the two profile edges areideally touched at any desired point by a line 20 perpendicular to the plates 318. z A flexible fiat material 320 such as sheet métal orthin (5 mm) plywood is optionally fastened to theprofile edges 319. ......The sheet métal can itself hâve a reflecting surface. 25 Mirrored foil or a thin glass mirror must be applied toplywood. A plurality of these mirror flûte éléments 317 arearranged such that above ail in spring and autumn at 12noon the solar radiation reflected by the individual 30 mirror flûte éléments 317 can be absorbed on as small asurface 321 as possible.

This design of the concentrating mirror can be wellintegrated on a house roof in terms of construction andarchitecture: 35 The optical concentration factor is also still good enough when only the absorber 322 is tracked and-the mirror is permanently connected to the house roof. - 85 -

The edges of the mirror segments 323 emphasize thevertical, and so the mirror is more easily accepted asa roof in emotional terms. A flûte 324 in which water can run off is arranged5 between two mirror éléments.

The mirror System thus forms the uppermost covering ofthe roof.

As an alternative to a solidly constructed building, itis optionally favourable to produce this structure with10 the aid of an appropriately shaped concrète flûte.

The described structure also has a favourable effecthere, since no horizontally running flûtes areconstructed in which water or wet snow can collect,something which can lead to the ingress of water,15 damage by frost and leakiness.

As an alternative, the mirror structure is optionallymoved about an axis.

Thus, it is advantageous when a surface perpendicularthereto pénétrâtes the mirror in a largely parabolic20 line and the absorber 322 is tracked such that androtated such that its main axis or axis of symmetry 325corresponds to the main direction 326 of the absorbedradiation.

The absorber 322 is in this case always located in the25 plane of symmetry of the parabolic fluted mirror 317, resulting in a good concentration ratio.

The core région of the absorber 322 comprises a fiattranslucent thermal insulation (=TTI) 327 which,together with an insulated container 328, surrounds an30 interior 329 from which the charged heat transfermedium (for example the heated air) is extractedthrough a pipeline System 330.

The absorber is arranged at a relatively large spacingof the order of magnitude of the extent of the TTI from35 the TTI, the side walls being mirrored so that a moreuniform radiation density occurs at the absorber. -The insulated container 328 with a reflecting innerwall forms the rear wall of an upstream solar collector 011343 - 86 - 331 which feeds energy to the heat transfer mediumbefore it can flow through the TTI 327.

This collector 331 is supplied with solar radiantenergy, which the TTI 327 has just been missing, 5 by a further mirror 332 connected to the absorber 322.

In the case of this collector 331, as well, theabsorber 333 is flowed through in the beam direction bythe heat transfer medium, which is fed to the entireabsorber structure by the pipeline System 334 via at 10 least one movable connection.

The absorber structures 322 of a plurality of mirrorsaligned in parallel and having identical focal lengthsare linked relatively directly to a co-moving pipelineSystem 334. 15 An absorber is movably connected to three fixed pointsvia three gear racks, and the spacing can be changed ineach case by a displacement in the rack direction underthe control of motor power.

At least one absorber 322 is displaceably connected to 20 a gear rack in the rack direction under the control ofmotor power, which rack is movably connected via two ' further gear racks to two fixed points in each case, and the spacing can be varied in each case in the rack direction under the control of motor power. 25 At least one absorber is movably connected to another absorber and is moved only with the aid of two gear racks.

The connecting tube 334 of the heat transfer medium isused also to détermine the orientation of the absorbers 30 322, which are fastened thereon, with reference to the tube axis.

The rotation of an absorber about an axis of rotationperpendicular to the horizontal east-west axis and tothe axis of symmetry of the absorber in the main beam 35 direction is performed by parallel coupling with the aid of cables to a gear rack which at 12 noon runs. .as closely as possible on a vertical plane in‘ north-south direction, the points of rotation 336 of the cables • 87 · 011343 being arranged on a plane through the axis of rotation337 of the absorber 322 or the axis of rotation of thefastening of the gear rack on the absorber structureand are situated on both sides of these axes of5 rotation 337, ... and in the case of. a projection intoa plane perpendicular to the axis of rotation 337 ofthe absorber 322 also form with the connecting linethrough the axes of rotation 337, ... at least approximatelÿ parallelograms whose angles are ideally10 90° at 12.00 noon.

As an alternative to the cable structure jus.tdescribed, the rotation of an absorber 322 about anaxis of rotation perpendicular to the horizontal east-west axis and to the axis of symmetry of the absorber15 in the main beam direction is performed by parallelcoupling with the aid of racks to a gear rack which at.12 noon runs as closely as possible on a vertical planein north-south direction, the points of rotation of theracks being arranged on a plane through the axis of20 rotation of the absorber or the axis of rotation of thefastening of the gear rack on the absorber structureand in the case of a projection into a planeperpendicular to the axis of rotation of the absorberalso form with a line through the · axes of rotation at25 least approximatelÿ a parallelogram whose angles areideally 90° at 12.00 noon.

The gear rack is fôrmed by a carrier on which there isfastened a Chain in which a sprocket engages which isdriven by a motor via an irréversible gear. 30 The sprocket is guided on the chain by at least oneroller which is pressed from the other side against thecarrier. A gear rack can be set up vertically to such an extentand lengthened down to near the ground such that the35 absorber structure can be lowered down to near theground along this gear rack by moving the engagingdrive. - 88 - ' 011343

The fulcrum for the absorber structure with gasguidance channels 322 is further distant in the beamdirection from the large-area main mirror 319 than thefulcrum for the smaller mirror 332, arranged 5 additionally around it.

Consequently, in the case of oblique incidence theoptical error can be more effectively compensated, inorder to achieve a higher degree of collectorefficiency. 10 The translucent thermal insulation 327 comprises a fiatcarrier structure, arranged in the direction ofradiation, such as, for example, a plurality of slottedmétal sheets with slots arranged perpendicular to thedirection of radiation, which structure is surrounded 15 by a transparent structure and/or above ail by astructure which reflects in the direction of radiationand is made from glass fibres in the direction ofradiation.

Optionally in addition, or as a substitute to the glass 20 fibres, glass tubes or rods are optionally arranged inthe beam direction. z/ The collector 16 is completely covered by glass 23.

The TTI 327 is covered by glass 337 only to the extentrequired for -guiding the heat transport medium of air 25 in a flow sufficiently parallel to the TTI 327.

As a resuit, this TTI 327 is rendered insensitive tocontamination of the pipeline System, and no reflectionoccurs during transmission of the radiation.

The air flows are controlled, in particular in the case 30 of attenuated solar irradiation, such that more air isblown out of the collector 331 upstream of the TTI 327than. is exhausted by the TTI 327. In addition to thescreening of the TTI thus achieved by the build-up of ahot gas cushion, contamination of the TTI by unfiltered 35 outside air is thereby reduced.

Because of the tracking, the solar radiant energy is concentrated by the mirror structure aboveail onto the translucent thermal radiation TTI 327 of 89 - 011343 the absorber. The solar radiation wili penetrate atleast the front part of the TTI 327 predominantlywithout absorption/ and subsequently be absorbed in theabsorber structure. 5 The thermal energy can escape against the beam direction front the absorption région only after overcoming décisive hurdles owing to the TTI 327, since the thermal radiation of the absorber or of each emitting surface is largely absorbed only by surfaces 10 which hâve a relatively small température différence/ and in addition the convection is suppressed by the large, surfaces of the TTI 327, which subdivide the relevant convection space. A substantial portion of the thermal energy which has been transferred by the 15 processes mentioned into less hot régions of the TTI 11 is absorbed there from the flow of the heat transfer medium (for example air flow) in the beam direction.

This yields a curved température profile whose gradient increases decisively with increasing température. 20 Since the gradient on the cooler side the. TTI 11 becomes smaller with an increasing rate of flow of the / hëat transfer medium through the TTI 327 in the case of / · a constant température différence at the surfaces ofthe TTI, the flow of waste heat through the cooler25 surface of the TTI is reduced.

The absorber is subdivided into régions throughwhich flow is controlled as a function of température,in order to avoid thorough mixing of heat transfermedium with large température différences in the output30 manifold 330.

The cross section through which flow can occur is intended to remain constant in this région in the process. · This is achieved by virtue of the fact that the 35 throughflow is controlled by bimetals 339 of which in each case two are connected to a beam 340 as in the case of a set of scales, the suspension of two 011343 - 90 . corresponding beams being movably connected again to acentrally suspended beam.

The pipeline 330, through which the hot gas isremoved from the absorber 322, is sheathed with an5 insulation 341 with an outer surface 342 with goodthermal conduction and, optionally, good or sélectiveabsorption, which in turn is largely completelysheathed by a translucent thermal insulation 343 andruns in a space 344 which is flowed through by the hot10 gas of the thermal energy carrier circuit on the way to a.t least one absorber 322, and which for the alignmentat 12 noon in autumn is surrounded on the directlyirradiated side by a translucent insulation 345, whichcannot be flowed through, and from the other side by a15 mirror 346, the upwardly directed surface of which isadjoined by an insulation 347 and a weather guard andwhich reflects the incident light above ail onto theside of the inner tube 342 not directly irradiated, andis thus completely sheathed. 20 a bulk material store functions effectively in z thermodynamic terms and is designed with an acceptableoutlay by virtue of the fact that the bulk material 348flowed through by the heat transfer medium (for exampleair) is divided by at least one insulting interlayer 25 349, which cannot be flowed through, into concentric shells with a cylindrical latéral surface with avertical axis and outwardly curved base and topsurfaces, and the transitions 350, which can be flowedthrough, take place from an inner Shell, filled with 30 bulk material, to the adjoining outer shell throughopenings in the insulating cylinder latéral surface349, which . are arranged in the région of a planethrough the cylinder axis on both sides in each case,and the flow is guided by connections, which cannot be 35 flowed through, running in the région of this planesuch that the shells can be flowed through only in onedirection of révolution about the vertical cylinderaxis.

I . ο, . η 1 1 7 Δ 7 A transition between two half shells filledwith bulk material is possible only in the case of flowthrough a vertical shaft 351 via which it is alsopossible to exchange heat transfer medium. 5 As a resuit, by reducing the inflow channel in placesit is possible to control the flow such that only heattransfer medium in a narrow température range flows inthe shaft.

One of the outermost insulation layers 352 is10 flowed through from one bulk fill layer to the other. Adécisive curvature of the température profile is formedthereby, as a resuit of which on the basis of theshallower gradient on the cooler side only a lower rateof flow of lost thermal energy occurs on the cooler15 side than without the throughflow against thetempérature gradient.

The flow paths are lengthened by additionalsmaller barriers 355, which cannot be flowed through,in the horizontally running bulk material layers 353,20 above ail in the région of the cylinder axis 354.

As a resuit, these bulk material layers 353 are alsoflowed through in a relatively uniform fashion, theflow paths are approximately of equal length as in thecylinder latéral surface 356, and there is no25 unfavourable mixing of heat transfer medium afc adifferent température.

For the purpose of seasonal storage, the bulkmaterial store is heated in conjunction with thecooling of hot inflowing air and cool outflowing air to30 far above 100°C, and a few weeks later thermal energyis extracted from the bulk material store by air whichflows at approximately. 50°C into the outer région ofthe store and is extracted through one of the airchannels at 120eC - 150°C and subsequently cooled by a35 heat exchanger which heats water from approximately40°C to 100eC which is extracted from an insulatedwater réservoir in the lower région and fed into theupper région. . 92 - 011343

The waste heat from the heat engine operated asa hot gas engine is used in buildings to supply energyfor heating and hot water.

An accumulator is interposed in order to découplé the5 operation of the machine from the heat requirement in terms of time. A high synergy effect is achieved when the accumulatoris filled not with pure water but with biological wasteand faeces. 10 Particularly when the aim is seasonal heat storage, thefaeces are too hot in summer for décompositionreactions or biogas production to be able to proceed toa considérable extent.

This effect is used in a similar way in the 15 préservation of fruit.

The production of biogas can ensue when thisaccumulator is cooled in late autumn or winter.

Not only is thermal energy stored seasonally thereby,but there is also an indirect storage of biogas. 20 //

Claims (14)

93 CLAIMS 011343

1. A method for entropy transfer by means of at least one open periodical thermodynamic cyclic process including at leastone working volume filled with a working fluid, at least one central partial volume in the working volume, whichis located between two isothermal sectional areas andperiodically modified in size, wherein a flow of working fluidthrough the central partial volume takes place from oneisothermal sectional area to the other one, wherein an exchange of working fluid takes place at differentpressure levels and at different time periods (c-d-e, g-h-a, cf.Figs. 4-6, Figs. 8-9) from the working volume to at least onevolume having a largely constant pressure and/or from at leastone volume having a largely constant pressure into the workingvolume, wherein a modification of the working fluid température averagedthrough the working volume is concurrently brought about by theperiodical modification of size of the at least one centralpartial volume, wherein at least one central partial volume is modified in sizeduring the exchange of working fluid at a largely constantpressure, wherein the size of the at least one central partial volume, orthe ratio of its size relative to that of the working volume, islargely kept constant when (during a-b-c, e-f-g, cf. Figs. 4-6,Figs. 8-9) the pressure in the working volume is modified withoutexchange of working fluid, wherein heat is input or output in the range of the at least twoisothermal sectional areas, wherein one respective further partial volume borders on each ofthe flow section isothermal areas delimiting the at least onecentral partial volume, the working fluid in the partial volumes 94 011343 présents different températures, and the sizes of the partial volumes are modified periodically, wherein, during a time interval much longer in comparison withthe duration of one period of the cyclic process, either intakeof heat energy to or discharge of heat energy from the workingfluid in the working volume takes place with the aid of at leastone substance of at least one continuously or periodicallyincreasing and decreasing mass flow at a sliding température orat several température levels.

2. The method according to claim 1, characterised in thatthe intake of working fluid into the working volume and thedischarge of working fluid from the working volume each takeplace starting out from partial volumes having differenttempératures and being separated by one of the isothermalsectional areas in the range of which heat energy is taken in byor discharged from the working fluid.

3. The method according to claim 1 or 2, characterised inthat a further exchange of working fluid takes place at identicaltime periods and at approximately identical pressure levels.

4. The method according to any one of the precedingdaims, characterised in that the size of the at least oneworking volume is modified periodically.

5. The method according to any one of the precedingdaims, characterised in that the size of the at least oneworking volume is modified periodically, primarily in those timeperiods (a-b-c, e-f-g, cf. Figs. 4-6) during which no intake ordischarge of working fluid into or from the working volume takesplace. 95 011343

6. The method according to any one of the precedingdaims, characterised in that the at ieast one substance is theworking fluid.

7. A device for carrying out the method according to any one of the preceding daims, including at least one working volume (11, 8, 36-41, 43, 114, 131-135, 156,207-210, 281-284, 275-277) filled with a working fluid (301, 310)in a pressure vessel (1, 128, 302, 288, 107), at least two flow passage means (11, 8, 36-41, 43, 114, 131-135,156, 207-210, 281-284, 275-277) capable of containing a flow ofworking fluid therethrough, for confining at least one centralpartial volume (11, 36-41, 131-135, 207-210, 281-284, 275-277)periodically modified in size in the working volume, at least one means (21-24, 29-32, 55-91, 117, 150-155, 298-300)for periodically modifying the size of the at least one centralpartial volume, so that a modification of the température of theworking fluid averaged through the working volume is concurrentlybrought about thereby during the working fluid exchange at alargely constant pressure, and the size of the at least onecentral partial volume, or the ratio of its size relative to thatof the working volume, is largely kept constant when the pressurein the working volume is modified without exchange of workingfluid, at least one means (146, 2, 22, 29-32, 113, 304-316, 11, 36-41,131-135, 207-210, 281-284, 275-277) for modifying the pressure inthe working volume, at least one means (18, 8, 11, 36-41, 131-135, 207-210, 281-284,275-277, 7, 43, 115, 156, 290) for intake of heat energy to ordischarge of heat energy from the working fluid in the workingvolume with the aid of at least one substance of at least onecontinuously or periodically increasing and decreasing mass flowat sliding température or at several température levels during a 96 011343 time interval much longer in comparison with the duration of aperiod of the cyclic process, wherein at least one valve (3, 4, 48, 49, 111, 112, 130, 129a,129b, 291, 294) is opened for the intake of working fluid ordischarge of working fluid from at least one or into at least onespace having a substantially constant pressure (13, 20, 19, 17)for the purpose of the exchange of working fluid at ifferentpressure levels, wherein heat energy is taken in by or discharged from the workingfluid and respective isothermal sectional areas interconnected bymeans of seal means (285, 288, 101, cf. Fig. 13) or thedélimitation of the working volume (1, 44) extend in the range ofthe at least two flow passage means (11, 8, 36-41, 43, 114, 131-135, 156, 207-210, 281-284, 275-277), wherein in the range of the flow passage means (11, 8, 36-41, 43,114, 131-135, 156, 207-210, 281-284, 275-277)one partial volumeeach periodically modified in size and having a differenttempérature borders on the side of the isothermal sectional areasfacing away to the central partial volume.

8. The device according to claim 7, characterised in thata regenerator (8, 11, 36-41, 131-135, 207-210, 281-284, 275-277)is arranged in the range of the isothermal sectional area whereheat energy exchange takes place.

9. The device according to any one of the preceding daims7 or 8, characterised in that a heat exchanger (7, 43, 115, 156,290) is arranged in the range of the isothermal sectional areawhere the heat energy exchange takes place.

10. The device according to any one of the preceding daims7 to 9, characterised by a control System (21-24, 29-32, 55-91, 117, 150-155, 298-300) for periodically moving the at least two flow passage means -(11, 8, 97 011343 36-41, 43, 114, 207-210, 281-284) against each other, to reducethe central partial volume between the flow passage means (11, 8,36-41, 43, 114, 207-210, 281-284) to the clearance volume duringat least one time period.

11· The device according to any one of the preceding daims 7 to 10, characterised in that the at least two flow passage means (114, 131-135, 156, 274-277)are fixedly mounted in the working volume, and the intermediatelypositioned, central partial volume is reduced to the clearancevolume during at least one time period with the aid of at leastone displacement member (279, 114, 142-145) periodicallyinterposed by the control System (117, 150-155).

12. The device according to any one of the preceding daims7 to 11, characterised by compressing means (2, 22, 29-32, 113,304-316) for periodically modifying the size of the workingvolume.

13. The device according to daim 12, characterised in thatthe compressing means for periodically modifying the size of theworking volume are a résonant oscillating System synchronisedwith the other periodical movements. (304-316)

14. The device according to any one of daims 12 and/or 13,characterised in that the control System is designed for controland feedback control of the compressing means. (2, 22, 29-32, 113)